Analysis of the Environmental Impacts of Crop and Livestock Activities in the Cerrado

and Its Inter-relationship with Water Resources in the Pantanal

Preliminary version Consultant: Andréa Aguiar Azevedo (ECO/ UnB)

Collaboration: Jorge Luiz Gomes Monteiro (GEO/UFMT)

1. Introduction

In recent years, an intensive movement has been observed related to the scarcity of water resources. The flow of many water courses, earlier considered unalterable, have arrived at the limit of their resilience1, where they can no longer replenish themselves by natural means. Many springs have dried up due to poor utilisation and incorrect management of these resources. Crop and livestock farming appear as the major activities responsible for the intense degradation of both subsoil and surface waters.

The Green Revolution, in the 1980´s, brought new hope to Brazil in terms of

agricultural productivity, with high hopes of bounteous harvests and new technologies which allowed the exploitation of little-used regions, such as the Cerrado of Brazil's Centre-West region. In fact many of these expectations were realised, however, the "environmental backlash" generated costs which were often without a solution or unredeemable, as for example, the loss of bio-diversity and the drying up of water courses through silting, in addition to pollution.

There are a variety of forms of degradation of water resources by the agricultural

sector. In the Upper Paraguay River basin (BAP), bordering the Pantanal, there are regions of the Cerrado bioma much exploited by crop and livestock activities. Intensive use of these mostly sandy soils, combined with poor soil management practices, potentializes a natural erosion process, with silting of the streams of the �planalto� (high plateau), which will eventually affect the rivers of the Pantanal. Associated with the erosion problem is the indiscriminate use of Agricultural Chemicals (ACs), especially in the higher altitude regions, where annual cropping is more intensive, also with unquantified impacts on the Pantanal ecosystem. Efforts have been made to make less aggressive ACs available on the market, but these products are still costlier, and thus less utilised. The inspection and monitoring of the use of ACs are still precarious in Brazil, in spite of "rigorous" legislation. Zulauf (2000, p. 89) warns that independent of the evolution of production technology, the use of ACs is one of the most serious factors in the deterioration in the quality of water resources.

Another form of water use, irrigation, among so many other technologies, is

capable of increasing production, optimising land use intensity. It effectively supports cropping activities during periods of the year when rainfall is inadequate for growing crops, especially in the Centre-West region. Various aspects of irrigation require examination, such as water use, economic efficiency, the environmental costs of the technology, etc. Studies have shown that, with a water use plan and good management, it is possible to increase crop production taking into account an environmental optimum. This implies respect for the physical limitations of the region which requires a detailed analysis to achieve acceptable levels and impacts on the environment, the main factors to be considered are topography, soil type, crop evapo-transpiration rates, rainfall and others. Irrigation represents the major portion of world water use - about 70% - and efficiency is still very low; estimated average world losses are between 50 and 70% (FAO, 1998, in Rebouças, 2001).

Alternatives for a more sustainable agriculture have been researched. Agenda 21,

brings out in Brazilian agriculture many of the challenges which the agriculture sector 1 Resilience is the capacity of an ecosystem to regain its original condition or a stable situation, after a de-stabilising event.

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still has to face in relation to the environment. But much work remains to be done to ensure effective change towards new paradigms for agricultural production. However, the agro-ecosystems should not be managed with the sole objective of conservation of water or other specific resources. There needs to be a systematic vision where all inter-acting elements are utilised in a way that economic rationale is integrated with basic ecological principles. Thus there is a pressing need to protect ecosystems which are notably unique and/or fragile, or to use them with great caution.

This study has as an objective to investigate which of the principal ecological

processes are being affected in the BAP biomes - Cerrado and Pantanal - by the unchecked expansion of agricultural activities. With this aim, after this introduction, the report is divided into several parts, to enhance its comprehension. In the methods and procedures section, there will be a brief description and characterisation of the study area, the basin of the Upper Paraguay River (BAP). This region was chosen for its immeasurable risks to the water resources, fauna and flora, which form the Pantanal. Within this basin, the principal factors involved in resource degradation, chiefly of the water resources, are concentrated in the upper part of the basin. Here, the Cerrado biome requires priority attention as a means of pre-empting further anthropic alteration.

A description follows of the agents which affect the principal natural resources

of these environments, deriving from cattle and cropping activities and its sequels. In addition, an evaluation was made of the most fragile sub-ecosystems in the wider biomes, pointing up the possibly endangered species of flora and fauna threatened by the agricultural expansion in the Cerrado. In the fourth section, the impacts of the utilisation of ACs in the agro-ecosystems will be further elaborated, with specific details on the study area (BAP).The fifth section contains an analysis of the present situation of irrigated agriculture in the Cerrado biome, emphasising the Centre-West region of Brazil, within the BAP. The final section comprises an analysis of the principal aspects mentioned in the report, as well as some suggestions for better standards for water users in agriculture and management systems with lower environmental impacts.

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2. Methods and Procedures

This report was carried out with an exploratory search of the bibliography on the subject matter. Priority was given to references having in their scope research on the impacts of crop and livestock activities in the BAP. Studies from other regions were also consulted. A number of interviews2 were carried out with specialists and technicians from private and government entities related to the topic of this research. Also, entities such as the Brazilian Agricultural Research Enterprise (Embrapa) and federal universities were prioritised in the interviews with a number of research workers. Technicians who work directly with farmers were also consulted, since they represent the pragmatic reality of the field.

The choice of the BAP is justified by its unique characteristics and, at the same time, because it is an important agricultural region in both Mato Grosso (MT) and Mato Grosso do Sul (MS) states. The juxtaposition of highly productive and profitable agricultural areas and one of the largest flooded ecosystems of the world, with an extensive watershed, besides immense bio-diversity (both animal and plant), makes this an essential and interesting area to study. The BAP has an area of 540,000 km2, with 346,301 km2 in Brazil, covering the South and Southwest of MS and the West and Northwest of MS3. The topography of the region is the same as that typical of the Centre-West. On the flat tops of the plateaux the watershed is not clearly defined, meaning that the watersheds of the different river basins are contiguous. The BAP comprises one large depression, the Pantanal; on the Brazilian side, this is skirted by elevated plateaux, interspersed with depressions. The plateau soils are principally latosols and quartz sands, podsolics are found on steeper lands and the more rugged terrain of the plateau scarps is characterised by lithosols and cambisols (FEMAP, 1999, p. 20). In the Pantanal there is a predominance of gleys and hydromorphic laterites.

The tropical humid climate (AW) of Köppen's classification predominates, characterised by a summer rainy season and dry winters. The temperature increases from South to North in the BAP. Rainfall is heaviest at the Northern extreme of the basin, exceeding 2000mm in places, while in the South, in some of the depressions, only 1000 mm/yr average precipitation is recorded.

The population of the BAP comprises 1,839,050 inhabitants, covering 76

municipalities (31 in MS and 45 in MT); the largest urban agglomerations are formed in MT, including the capital, Cuiabá.

2 See Annex I for the list of names. 3 The national Water Agency gives a figure of 363,592 km2

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3. Agriculture and Natural Resources

From its beginnings, the conquest of nature by man, transformations began in the environment - agriculture is a notable form of appropriating nature's space. Using the concept of ecological sustainability4 in the strict sense, it could be said that at this point the environment was already affected. In order to utilise his abilities and fulfil his desires, man has to exploit nature. The big problem has been the way is which he did it. In order to develop, man completely ignored that he too is subject to nature. The discipline of ecology has long since raised the alert about resiliences in ecosystems, but only when the science of economics (in the domain of the humanities) signalled that this forma of exploitation was beginning to be "expensive", did those directly involved in the use of natural resources begin to pay attention. This scenario could be found in any production area, but focussing on agriculture, it can be observed that farmers and government took a long time to perceive that the mode of exploitation of agro-ecosystems could be, in many cases, unsustainable through exhaustion of natural resources, such as water and soil, which are the most directly involved in this type of production activity. From this realisation arises the urgency to search for new standards of production, where ecological sustainability has a threshold level of respect, not forgetting economic sustainability. To the contrary, such changes will not last very long. But how has been the relationship of Green Revolution production practices with natural resources?. In a very succinct form, the Agenda 21 for Brazil showed this cycle of agricultural degradation, which is represented in Figure 1, below. Figure 1. The cycle of degradation in agriculture (Agenda 21)

Contamination of groundwaterand water courses.

Use of agricultural chemicals

Use of fertilisers

Erosion

Land clearing

4 "In the most rigorous definitions, sustainability is the capacity of an ecosystem to maintain a constant state over time". (Kitamura, 1993:47). Sustainability of an ecosystem occurs when the balance between the inflows and outflows of matter, energy and information is maintained (Glico em Kitamura, 1993:47).

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According to this figure, the removal of the original vegetation is responsible for the loss of a major fraction of bio-diversity in situ, leaving the ecosystem more vulnerable to a reduction in its resilience. Inadequate ecosystem management is the cause of a serious environmental problem, erosion, especially the laminar form5. With the soil losses caused by erosion, there will be a lack of plant nutrients which, very quickly, will generate the need for fertilisers. Excessive use of inorganic fertilisers can prejudice the biological quality of plants and contaminate water resources, besides depleting the soil microfauna, which inhibits the natural enemies of crop pests and diseases. Without natural predators, insect pests and disease multiply and to combat these "agrotoxics" (ACs) are used, such as insecticides, fungicides and others. These ACs depend on an active ingredient that may have long residual effect and contaminate the groundwater and other water bodies, besides entering into the food chain of ecosystems and, ultimately, contaminating man.

Kitamura (1993) adds that, besides the environmental problems described, generated by agriculture, there is a further problem, derived from the concentration of economic activity, notably the question of land tenure allied to "conservative modernisation". The skewed development of technology has caused the exclusion of the small farmer who, generally, is forced to use management systems which impact much more on the physical and biological environment than those of the large-scale farmer. In many cases this is the only way he (the small farmer) knows to survive. Besides this form of pressure on water resources, there is direct extraction for irrigation purposes. This relationship is detailed later in the study. At this point, the interference of agriculture in some of the ecological processes of ecosystems will be analysed, emphasising the Cerrado and following the scheme presented in Figure1.

3.1 De-forestation and bio-diversity

Government plans for expansion of the area of crops and pastures in the Cerrado and the Amazon in the decade 1970-1980 provoked intense occupation of the BAP, especially on the fringes of the Pantanal, which are elevated areas, not subject to flooding. In accordance with a study of the Pantanal (PCBAP, 1997) which utilised satellite imagery and ground truthing, only 3.9% of the total land area had been cleared in 1990/91. By 1993, this had reached 5.2% (7,280 ha??) detected by direct methods. However, this low incidence of de-forestation can be credited to several factors, among which the fact that being a flood plain, its occupation is regulated by its hydrologic regime (Silva et al, 1998). Besides this, the existence of extensive natural pastures in these floodlands, the predominant activity is cattle raising. The small areas of cropping which exist are basically for subsistence, however, there are fertile soils in the Miranda and Nabileque region, where rice is grown on the flood plain, on the left margin of the Miranda River (Silva et al, 1998, p. 1743).

Considering that the major part of the Pantanal flood plain occurs in MS,

66.9% of the de-forestation in the Pantanal occurred in MS and 33.1% in MT. The municipalities which have the greatest cleared areas are: Rio Verde de Mato Grosso, Porto Mutinho, Santo Antônio de Leverger and Corumbá. The areas most affected by de-forestation were savannah forest ("Cerradão"), tree savannah ("Cerrado", "Campo

5 Laminar erosion is characterised by the loss of topsoil. Soils without vegetative cover are the most vulnerable.

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Cerrado") semi-deciduous/dry forest ("Mata Seca", "Mata Calcaria") and savannah steppe ("Mata Chaquenha") (Silva et al,1998,p.1744).

In the Planalto, the situation is different. This area is characterised by intense

and disorderly de-forestation, above all of very sandy soils. Of the land cleared in the BAP up to 1994, 93.72% occurred on the Planalto (predominantly of cerrado vegetation) and only 6.28% on the flood plain (Silva and Abdon, 2000). In this area, cattle raising predominates, especially in MS. In spite of this, there are areas with high technology crop production, notably on the table-land. On the edge of the Pantanal, on the east side, the highest pressure for land clearing is found in the old land holdings of Rio Verde do Mato Grosso, Santo Antônio de Levenger and Coxim. There is also an intensification of land clearing in the areas which flank the Itiquira and Taquari rivers, this last showing an accentuated process of erosion.

Among other losses for the ecosystem, it is known that the loss of bio-diversity

contributes significantly in the reduction of its resilience. The Cerrado was always considered by many government entities and also by farmers to be a biome of little economic value and poor soil. For this reason, it was always forgotten, especially, in policy making. At the present time only 20% of the native Cerrado vegetation remains intact in Brazil6. Conservation International7 considers that the Cerrado - which occupies 2 million km2, about one quarter of Brazil's territory, covering 10 states - is amongst the 25 most threatened ecosystems of the planet, in terms of conservation. However, only 3% of its area is protected in conservation units and 60% has already been profoundly altered by man.

On the Planalto, especially the tree savannahs on the table-lands are being

completely substituted by mechanised crops, with monoculture of soybeans (sugar cane) and cotton predominating. In the latter crop, many rare or localised species can be extremely vulnerable. In the study carried out by PCBAP (1997) several of these species are mentioned, among these are Dilkae margaretae (passion fruit tree), Lychnophora sp. (a genus of medicinal plant) Gomphrena officinalis (ginseng), Esterrhazia splendida (an ornamental specie), Zornia fluminensis (a forage legume). Beside this, the study shows that there is extensive degradation of the flooded valley-bottom vegetation, the Mauritius palm groves and the headwaters of streams through silting direct or indirect de-forestation. This causes an imbalance with the influx of invader species such as bullrush ("taboa" - Typha dominguensis) and Brachiaria arrecta. This invasion has repercussions on the ichtyofauna and the remaining groups of aquatic fauna and is already occurring around the headwaters of the Pantanal�s rivers. Also, since types of African graminea, like Brachiaria decumbens plus Andropogon gayanus and in a lesser degree Hyparrhena rufa ("Jaraguá") are also very invasive and extremely competitive with the native graminea and herbaceous plants of the camps (�campos�- flat areas of grass vegetation) and the Cerrado. On the Chapada dos Guimarães, in the National Park, these species occur as more important modifying agents than human trampling or fire (Id, Ibid: p.33-34).

Another study executed between 1974 and 1986 already showed that a number

of species were threatened in MS. Conceição (1987) argues that the principal motives are the use as an energy source for industry as well as the expansion of crop production and cattle raising. Apart from this is the fact that no re-forestation plan is being 6 Data from WWF Brazil website - http://www.wwf.org.br/bioma/bioma.asp?item=10. 7 A NGO present in 27 countries

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executed. Another point to be emphasised is that when replacement of the vegetation occurs, sometimes pure monocultures are established with species exotic to the local environment. The same author already warned that the dis-characterisation of the "cordilheiras" (small elevations), the isolated vegetative formations ("capões") and the gallery forests is occurring in a notorious manner, via the conversion of these areas into gramineous vegetation.

Amongst the plant species potentially affected, the study detected 10

threatened species, 19 very vulnerable and 11 vulnerable species (see table in Annex A). In the list of the most threatened species are some popular ones like "aroeira" (Astronium urundeuva), "piqui" (Caryocar brasiliensis), "pau ferro" (Caesalpinia férrea), "jatobá mirim" ( Hymenaea stilbocarpa), among others. Beside these, in The Brazilian Institute for the Environment's (IBAMA) list of plants threatened with extinction (1992), there are some which occur in the BAP. Mahogany (Swietenia macrophylla), "cerejeira" (Torresea acreana) e Aspilia grazielae are included in these.

Lost species are not only important for their economic value but as regulators

of the ecological cycles within the ecosystem. For example, the removal of tree and brush vegetation directly influences the hydrologic cycle, through the loss of water from the transpiration of plants, notably in conventional tillage, where soil is left without cover. Apart from this, another argument for preserving part of the vegetation (in reserves) is that a number of species can only complete their life cycles in these sites. When all the original vegetation has been removed, crops frequently are invaded by these species, called "pests", which seek food in the only place left available. The document on bio-diversity produced by the Brazilian Ministry of the Environment in 19988 indicates the following goods and services offered to agriculture by the maintenance of bio-diversity, which ensures productivity and environmental quality:

• The stock of organisms permits natural biological control; • The participation of live organisms in the maintenance of natural cycles of

water, energy, nitrogen, carbon and others; • Pollination on which crops depend; • Symbiotic associations; • Genetic resistance which may come from wild species; • New species of economic importance.

The importance of the micro-fauna and micro-flora, which are present in agro-

ecological environments and that of pollinating insects, should be stressed. Besides the decomposition of soil organic matter (SOM), symbiotic organisms

promote the absorption of nutrients, such as nitrogen, avoiding extra costs with these inputs and avoiding pollution of watercourses.

Another question which generates polemics is the burning of pastures on the

Planalto and in the Pantanal. The use of fire is an old practice in the Pantanal, with various adepts who justify controlled use as an important instrument for preventive large bushfires. In this scenario cattle production is a great partnership, because the cattle eat the large tussocks of grass which are veritable powder kegs, when dry. This makes so much sense that the steer has been called the "fireman of the Pantanal" (Pott in Barros,1993). Besides removing the dead grass, little consumed by the cattle and other

8 The first "National Report for the Convention on Biological Bio-diversity" Brasília, MMA, 1998.

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animals, the fire also stimulate the sprouting of new and palatable grass leaves (PCBAP, 1997: 31). However, caution should be exercised to avoid indiscriminate use of fire, without adequate protection to prevent it spreading to other areas, such as the elevations �cordilheiras� with Cerradão vegetation, isolated forest areas (�capões, sing. capão�), swamps and bottomlands, which do not require burning, on the contrary, they need protecting.

Besides the importance of bio-diversity in situ for the maintenance of the

ecosystem, the BAP is also an important germplasm area. There are useful species , not only for medicinal use, but also with economic value, as those of the genus Manihot (maniocs or cassavas), types of passion fruit bushes and wild peanuts, which are endemic (PCAAP, 1997).

Studies carried out by the Embrapa Pantanal technical team show that there are

95 mammalian species, 665 bird species, 162 reptiles species, 40 amphibian ones and over 1,100 butterfly species in the region of the BAP, including the Cerrado of the Planalto. Of the animal species detected as being in danger of extinction in this study, many coincide with the vertebrates which are considered under threat in the Cerrado ecosystem in the official list of IBAMA (ministerial decree 1522 of 1989).

The species threatened with extinction are: "coatá-preto ou macaco aranha"

(Ateles paniscus), "ariranha" (Pteronura brasiliensis), "lontra" (Lutra longicaudis), "cachorro-do-mato-vinagre" (Speothos vinaticus), "lobo-guará" (Chrysocyon brachyurus), "cachorro de orelha curta" (Atelocynus microtis), "jaguatirica" (Felis pardalis), "onça-parda" (Felis concolor)9, "onça-pintada" (Panthera onca), "gato palheiro" (Felis colocolo), "gato do mato" (Felis tigrina), "gato do mato pequeno" (Felis geoffroyi), "maracajá" (Felis Wiedii), the "veado-campeiro" (Ozotocerus bezoarticus), "cervo-do-pantanal" (Blastocerus dichotomus), "tatu canastra" (Priodontes maximus) and "Tamanduá-bandeira" (Mymercophaga tridactyla). From birds, the species threatened with extinction are "arara-azul" (Anodorhynchus hyacinthinus), the "bicudo" (Oryzoborus maximiliani) and the "jacutinga" (Pipile jacutinga).

3.2 Soils and their ecological functions

Based on a serious of physical, chemical and morphological denominations criteria have been established to differentiate soils. In the Cerrado area, the two soils which predominate are the Dark Red Latosol (LE) and the Red Yellow Latosol (LV) - Lobato and Richey (1980). In general, these are deeper soils and present high aluminium saturation, which can be toxic to crops. The LE has a higher clay content and the LV a lower one. In contrast, the latter has a higher sand content (60% on the 0-20 cm depth) (Id, ibid,1980), which gives it excellent drainage but with a high leaching tendency for crop nutrients. Probably, one of the great problems in the accentuated silting of the Pantanal rivers resides in the fact that the soils with this texture are widely used for crop and livestock production. Soil with high sand contents lose their structure with great facility, strongly influencing the erosion process. These sandy soils are very common on the Planalto of the BAP and in MT they extend over 261,997 km2. They also occur on the Planalto of the Parecis - the confluence between the Amazon basin and the BAP - on the Planalto of the Guimarães, extends eastwards to Barra do Garças and Araguaiana (Ferreira, 2001). However, it is also interesting to emphasise that the 9 Apesar de alguns pesquisadores concordarem que este não é um animal que deveria estar nesta lista, ele consta na lista oficial do IBAMA. Esta lista está disponível.

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heavy soils, by virtue of their deficient drainage, can suffer from compaction problems, if not well-managed.

Soils are formed and also modified as a result of their mineral matrix, the

topography, the climate and the living organisms that they contain (Guerra; Cunha, 1966). Thus we cannot consider them as static entities. Their dynamics occur as a function of modifications in these factors, which may be natural or caused by man.

Crop production depends on the type of management of each crop and greatly

modifies the quantities and availability of chemical elements in the soil, its physical characteristics and its biological components. According to Gleissman (2001), some basic characteristics serve as parameters for the evaluation of the origin and state of conservation of the soil. These are:

• Texture: this is, defined by the particle size of the soil minerals (gravel, sand, sill and clay). The clay fraction controls the most important soil properties, such as plasticity and ion exchange between particles, with water and with the soil. However, clay may cause drainage problems and, when dry, cause cracking (p. 217).

• Structure: this is the appearance of the soil's macro-structure, or how the soil particles join together, giving rise to different sizes of aggregates and structural forms. From the agro-ecological perspective, a good aggregate structure is of considerable importance, because particles which bind together, resist wind and water erosion, even during periods of the year when vegetative cover is minimal (p. 219).

• Colour: this is important, in that it permits identification at first glance, besides revealing a history of the soils development.

• Cation Exchange Capacity (CEC): this is determined by the greater or lesser capacity to adsorb of nutrients and governs their respective uptake by plants.

• Acidity and Soil p.H.: represents the equilibrium between acid and base radicals. When p.H. is very high or very low (p.H. neutral = 7), the availability of nutrients is affected and plant toxicity may also occur. Acidity may be altered by natural processes but man's interference exacerbates this, since one of the forms of acidification is the leaching of bases and also their removal occurs due to uptake by plants, which absorb nutrient ions (p. 233).

• Salinity and alkalinity: salts exist naturally in the soil, from intemperization of the material of origin and/or in situations where there is scarce rainfall and high evaporation. However, in irrigated crops, continuous or inadequate fertilisation with fertilisers of a high salinity index, such as potassium chloride, induces salinisation problems in the root-zone, as well as favouring eutrophization of the water sources (Gomes et al, 2000, p.31).

Fertilisation Many substances in the soil play important roles in plant nutrition. Their concentration depends on their rocks of origin, which served as matrixes for their formation, besides other factors. In natural ecosystems, plants are able to sustain themselves through the re-cycling of these nutrients around the various compartments of the agro-ecosystem - air - soil solution - plant - in a dynamic equilibrium. However, with agriculture, the system opens up, because there is a loss of nutrients through harvest take-off, leaching and volatilisation. In this manner, the

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replacement of nutrients become necessary and this can be effected by organic or inorganic (mineral) fertilisation. In the present context of large-scale mechanised agriculture, the fertilisers which are used are inorganic, which, in excess, can bring a number of problems. Gomes et al (2000: p.40) observe that applications in excess of the plant's needs provokes luxury uptake of nutrients by the plant and increases the availability of these elements in the soil-water system, resulting in an imbalance in the environment, besides causing a reduction in the biological quality of the plant. One of these imbalances, is generated by the increase in nitrogen and phosphorus via diffuse sources deriving from crop cultivation. Nitrogen can enter ground and surface water, principally via leaching, while phosphorus is transported principally in surface runoff. Eutrophication occurs when the increase of these nutrients in the water stimulates algal "blooms", increasing the organic matter in the water. This event influences other parameters which affect water quality, such as the Biochemical Demand for Oxygen (BDO) for the metabolism of the algae in the aquatic environment; this provokes a lack of oxygen in the water. In extreme cases of scarcity of this gas, mortality of fish and other organisms of the of the aquatic biota occurs. Below, Figure 2 shows the principal processes involved in the eutrophication of water resources (Corel,1998 and Gomes et al,2000: p.29).

Figure 2 . Processes involved in eutrophication.

Oligotrophic: environment with low organic matter (OM) Mesotrophic: moderate OM Eutrophic: high OM

Figure Translation Produção primária: primary production Biodiversidade: bio-diversity Oxigênio dissolvido: dissolved oxygen Input de P: P input Observing the figure above, the effects mentioned earlier become clearer, such as the increase in primary production (algae) through introduction of phosphorus into the system, contrasting with the reduction in dissolved oxygen and consequent loss of bio-diversity.

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Nitrogen and phosphate fertilisers have maximum limits of tolerance for drinking water. The nitrites generated by the reduction of nitrates are toxic for human and animal health. The maximum permissible levels are 10mg/l of nitrate (N-NO3) for drinking water in many countries. Some juvenile animals can suffer intoxication at concentrations of 5 mg/l of N-NO3 through water ingestion. Older animals can be affected by a reduction in milk production, deficiency of vitamin A, thyroid disturbances and reproductive problems (Pimentel, 1996; Gomes et al, 2000). The phosphate fertilisers, besides the problem of euthophication, which is still not very serious in tropical countries10, contain in their composition radioactive elements such as Uranium and Cadmium, to which farmers are exposed, either directly or by inhalation (Gomes et al,2000). The biggest problem of organic fertilisers, principally those generated from urban and industrial wastes, is that they can contain unknown elements and heavy metals and there is still much uncertainty over the potential consequences of their use on ecosystems and human health derived from these unknown compounds. More intensive study of these products, which agriculture demands, is the responsibility of the scientific community, in an effect to avert greater environmental problems, (opus cit)

3.2.1 Cerrado soils and their importance in the erosion process Various criteria are used to evaluate the erodibility of soils, such as soil type, relief, drainage and rainfall. According to Veneziani et al (1998) more attention should be given to geological/structural factors in this analysis. The physical-chemical-mechanical properties of soil type are directly related to the potential for the breakdown of soil structure and soil erodibility. Rainfall events, winds and insolation are some of the natural factors which arise as modes of facilitating or accentuating this process. Or, naturally "erosion depends on existing relationships between the erosive capacity of the rainfall and the surface and subsurface flows and also of the susceptibility of the materials to erosion" (Mafra, 1999: p.302). Also, the activities of man, such as agriculture, can accelerate this process. This last factor could be reduced if adequate conservation and management practices were adopted in working the soil. The two most common types of erosion are laminar and gully erosion11. In the BAP, referring to that part of the Cerrados located on the table-lands, laminar erosion occurs, which, by means of being little perceived, can cause a significant problem of soil loss, generating fertility decline and long-term cost repercussions. The progressive reduction of the surface layer of soil caused by laminar erosion can affect root growth and water percolation12 into the soil, to the point of reducing biomass production and, consequently, the protection of the soil (opus cit.: p. 308). In the transition areas between the higher land and the flood plain, significant erosion can occur, as for example, indicated in Figure 3. Here one sees a gully in an advanced stage, in the municipality of Alcinópolis. MS. 10 Cunha et al (2000) indicate that this problem until now has been concentrated in rich countries which use more of these fertilisers, for the soils of tropical countries show a high phosphorus fixation capacity besides having deeper profiles, which limits leaching. 11 The difference between laminar and gully erosion is that the former provokes soil loss across the whole surface while the second is produced by linear concentrated runoff, producing risks and then gullies. 12 Percolation is the action of penetration of water into the soil.

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Figure 3. - A Gully in the Upper Taquri Basin

Source: Padovani,C.R.� Embrapa Pantanal (2000). Another cause of erosion generated by agricultural activity is localised and repeated trampling of cattle, which causes compaction, providing a site for surface runoff, as can be seen in figure 4. Figure 4. Area of pasture on a slope, showing an erosion rill caused by cattle. Also, in a study carried out by Embrapa Pantanal (Corumbá, MS), on the catchment of the Upper Taquari river (BAT), within the BAP, critical areas of advanced erosion ands silting were detected, similar to that observed in Figure 5. This is an area on the Planalto, where the water courses are disappearing. Figure 5. Silted-up watercourse located in the municipality of Alcinópolis (MS) Source: Padovani,C.R.� Embrapa Pantanal (2000). The next picture (figure 6) shows inadequate planting practice in a sloping area, with the formation of the first rills. Figure 6. Erosion process caused by poor management. In the background is the watercourse.

Source: Padovani,C.R.� Embrapa Pantanal (2000). From the above picture it can be noted that part of the eroded material remains in the watercourse, contributing to its silting up and ultimately carrying more sediment to the Lower Pantanal Basin. Some researchers question the degree to which man's activity impacts on the Pantanal, in the sense that it is an alluvial basin, formed by sediments. A clear example was given by Adamoli (1995) when he emphasises that the River Taquari, over its history, formed an alluvial fan of 50,000 km2 ; this process silted up many water courses and formed others. Figure 7 shows a breach of the river bank and water flow out over the Pantanal flood plain. This process alters habitats and floods native pastures, forcing the retreat of cattle raising activities. Figure 7. A breach in the bank of the River Taquari on the Pantanal flood plain.

Photo: EMBRAPA Campo Grande (MS)

12

There is no doubt that, in spite of this being a natural process, it is being excessivily accelerated by the actions of man. In this specific case it contributes considerably to the bursting of river banks. But, to what point man's actions influence the changes one still does not know. However, the foregoing figure is a demonstration of this course of degradation, that puts at risk the water resources, the activities which derive from them and the species dependant on them, besides agricultural activity itself. The native vegetation, principally the tall dense forms, contributes much towards avoiding erosion (Veneziani et al, 1988).This way the kind of vegetative cover can imply in greater or lesser loss of soil. Table 1, below, based on studies done in Campinas-SP, show these differences. Table 1. Erosive effects of different vegetative covers.

Land Use Erosion (ton./ha./yr) Runoff (%) (surface flow)

Forest 0,001 1,1 Pasture 1,0 1,6 Coffee 1,4 1,6 Cotton 36,0 8,2

Source: Lal 1990 in Mafra 1999: p.309. It is pertinent to emphasise some characteristics of the Upper Taquari basin, mentioned earlier, given the quantity of references on the subject and its tendency to erode. Its headwaters occur on the Planalto of Mato Grosso state in the direction of Coxim-MS and from there flow to the Pantanal plain. The high concentration of summer rains and the friable nature13 of the substrate, with a predominance of unconsolidated sandstone, cause the high levels of erosion and consequent sediment transport to the lower reaches of the river in the Pantanal (Santos and Crepani, 1993 in Oliveira et al, 2000: p. 9). Adamoli (1995) comments that the very reduced slope (10-15 cm/km) of the Taquari river in the Pantanal effectively increases this silting problem. Besides this, the sandy to moderate textures in areas of accentuated slopes accelerate the process. This panorama can be observed through the photo-interpretation of images of the R.Camapuã (Figure 8) in the R. Taquari catchment, where several sandbanks (white dots) along the course of the river are in evidence, besides gully areas14. Figure 8 - Photograph of River Camapuã (Taquari Catchment) showing sand banks deposited on the river bed.

Through a study carried out on soil losses15 in the catchment of the Upper Taquari river, in 1994, the most critical regions were apparent as the municipality of Alto Araguaia-MT, with a soil loss potential of 990 t/ha-1/yr-1 , well above the average loss for the basin (555.6 t/ha-1/yr-1). Other municipality in a preoccupying situation are Costa Rica-MS, Rio Verde de Mato Grosso-MS, Alto Taquari-MT and Alcinópolis-MS.

13 Refers to the strong tendency to fragment. 14 In this pasture, green is Cerrado vegetation and magenta or lilac is pasture. The lighter the lilac colour, the greater the area of exposed soil and the greater the erosion problems 15 Soil losses in the BAT were evaluated using the Universal Soil Loss Equation (USLE) via photo-interpretation techniques and computer routines (Galdino et al, 2000, p. 67)

13

The estimated soil loss of the BAT, in 1994, was estimated at 70.39 t/ha-1/yr-1, which is considered a high erosion rate (50-200 t/ha-1/yr-1 - Galdino et al, 2000: p.67). The degree of erosion increases proportionally to the increase in de-forestation in the basin. In the period from 1977 to 1991, a 50% increase in the area of planted pastures and crops was detected. Still worse, the Quartz Sands - the most susceptible to erosion - were those which showed the highest level of agricultural occupation (Oliveira et al, 1993: p. 8). At the present moment, the Alto Taquari region has 233,250 hectares (ha) in crops, with soybeans dominating (195,948 ha -IBGE, 2002). As to the pastures planted for livestock, the largest areas are found in Camapuã, MS (414,567 ha), Coxim, MS (247,382 ha) and Alcinópolis, MS (233, 677 ha). Below, in Figure 9, the Upper Taquari Catchment (BAT) is represented with its component municipalities. Figure 9. Location of the Upper Taquari Catchment, showing the municipalities which comprise the area on the Planalto.

Source: Oliveira et al, 2000

3.3 Water and the Agro-ecological System

Life forms have always been associated with an important element of nature. When the surface of other planets is explored, the mere suspicion of the presence of water is a sign of the existence of life. Life supposedly originates in the water and depends on it to survive. Amongst living beings, plants are the most sensitive to water, since they cannot migrate to satisfy their needs. In the course of the cycle of evolution, these communities adapted to the scarcity, or not, of water, thus permitting survival in a hostile environment.

14

The greater part of water which falls as rain on the earth's surface in any specific location, is not utilised by plants and animals, being lost by surface runoff, infiltration, evaporation and retention in the leaves of plants.

The water present on the earth's surface, in the oceans and in the atmosphere

moves from place to place and changes its physical state in a continuous and integrated movement called the hydrologic cycle.

This cycle involves four phases, according to Garcez e Alvarez (1988, p.3):

• Atmospheric precipitations (rainfall, hail and snow); • Underground flows (infiltration, ground water); • Surface flows (streams, rivers and lakes); • Evaporation (from water surfaces and soil), plant and animal evaporation.

The water reaching the soil surface can infiltrate as a result of appropriate soil

structure and favourable topographic conditions, or run off when the soil is saturated, reaching the lowest parts of the landscape, accumulating in depressions, or flowing away in rivers. Water which infiltrates into the soil returns to the surface after being absorbed and transpired by plants, or it is evaporated from the soil by the incidence of solar radiation, or it suffes an increase in temperature. Water also penetrates deeper into the soil, reaching the groundwater, feeding the springs along the catchment. The evaporation of the water from the surface of continents, together with the evaporation from the oceans, on reaching higher altitudes, condenses and is precipitated, giving continuity to the process.

The diversity of an ecosystem can be understood as a situation which favours

dynamic equilibrium in the environment. A different situation occurs with the agro-ecological system, which is characterised by a simplification of the environment, altering the regularity of the hydrologic cycle.

In Conventional Tillage, when soil is exposed, radiation incides directly on the

surface, intensifying evaporation from the soil. At the same time, the reduction in SOM reduces the action of micro-organisms in the soil and, as a result, soil porosity is reduced, limiting the penetration of water. When it rains, the surface run-off becomes intense, favouring laminar erosion, while concentrated torrential flows facilitate rill16 formation. If less water infiltrates, the groundwater is not fully replenished by the rain and the groundwater fails to act as a regulator of the level of water in the rivers. Reduced infiltration diminishes the availability of water to plants, which, in this manner become more subject to "water stress".

Many factors linked to agriculture have contributed to the environmental

deterioration of the Paraguay river basin. A series of substances has been added to the eco-system without which the intensive, high-yielding agriculture would not be viable. The lack of adaptation of the technologies adopted in the Cerrado, associated with non-compliance with the norms established by the Forest Code, have been responsible for the degradation of this ecosystem.

For a decade and a half,.destruction was synonymous with "development" in

Brazil's Centre-West. Growth of agricultural production was treated as a demi-god by the state, the farmers and agribusiness. Only the benefits generated by increments in 16 Rills are small furrows formed in the soil surface.

15

production, tax revenues, the establishment of new cities and job generation were important. For a long time, from the end of the seventies to the close of the eighties, the social and environmental impacts were ignored, or treated as marginal,.

In the name of progress, the original vegetation was substituted by exotic pasture

grasses and crop production., dependent on chemical inputs. Besides these, other activities were implanted in the Paraguay river basin, involving sugar mills and alcohol distilleries, integrated pig and chicken production projects, packing houses and slaughterhouses, soybean oil extraction plants and milk factories, which were followed by a population increase and accelerated urbanisation.

Monitoring carried out in 1997/98 involving the principal tributaries of the

Paraguay river basin demonstrated that the water quality in these rivers was satisfactory, with situations where the dissolved oxygen content of the rivers Itiquira (MT), Apa, Correntes and Piriqui showed analysis of excellent to good quality. However in other tributaries, such as the Cuiabá River, water quality varied from acceptable to very bad (FEMAP, 1999, p. 21).

Some water courses showed a variation in quality from very good to very bad,

including the Nabileque river. In the Pantanal stretch, the higher volume of organic matter and the lower flow velocity in the channel favour decomposition, altering the amount of dissolved oxygen. The monitoring did not show water contamination by chemical residues deriving from agricultural activities because the government agencies had not included these parameters in the survey.

In spite of the low intensity of crop production in the Mato Grosso do Sul state

portion of the BAP, when compared to Mato Grosso state, it still represents a threat, because the research organisations are constantly creating new varieties, adapted to fragile soil, which will, in the future, permit the incorporation of sandier soils into crop production that are today in pasture. The future trend is an increase in the cropped area, with consequent deterioration in water quality.

3.4 Priority Sub-ecosystems needing protection in the cerrado areas of the BAP

Some areas, because they have a certain ecological function within an ecosystem, or by virtue of being exceptional or unique or else giving shelter to endemic species, merit special attention with regard to preservation and conservation activities, One of the big problems of agricultural exploitation, especially crop production, is the total removal of the existing plant cover to make way for planting monocrops. Besides this, many landowners extend their plantings over areas of permanent preservation provided for in law, such as river and stream margins and steep slopes, amongst others. Another serious problem which occurs in the cerrado areas of the Planalto is that the headwaters of the rivers which form the Pantanal are often subjected to indiscriminate use. Very frequently, these are dammed and their flow interrupted or reduced; this occurs on watercourses in many land holdings. Another cause of water shortage is the clearing of these headwaters, as can be observed in Figure 10. As a result of the difficulties in identification and monitoring, the state has no control over this situation..

16

Figure 10. Headwaters of the Monjolo stream in the municipality of Chapada dos Guimarães (MT).

Photo: Mario Friedländer In the BAP, some areas such as groundwater outflow areas ("veredas"), flood plains, river gallery forests and the camps with gilga ("murunduns"), water courses and springs, gravely and steep areas are important and merit more attention from legislators and executive entities of government. Generally, these areas are called "redoubt areas" that are islands of vegetation and maintain productivity17 during the dry season. Later, a detailed list will be given of the ecological functions of these areas, present in the Cerrado Biome within the study area. "Veredas" (Outflow areas) "Veredas" are phyto-geographical formations within the Cerrado with groundwater outflows (or a water table very close to the surface) where moisture is always present. Thus, their soils are rich in humus and they have very characteristic vegetation, especially marked by presence of the Mauritius palm - Mauritia vinifera ("buriti") (Castro,1980,p.326). Their areas are well-defined, having a so-called envelope zone type of Cerrado around them. In the topo-sequence next comes the dry zone and a wet zone with grassy vegetation and small shrubs followed by the channel zone where there may be a continuous flow of water. In this latter site, groves of Mauritius palms ("buritizais")18 are characteristic. This description appears in diagrammatic form in Figure 11. Figure 11. A schematic cross-section of a "vereda".

Source: Castro,1980,p.329 Deriving from their abundance of water, the vegetation of the "veredas" is constantly green and serves as a refuge for animals such as "capivara" (a large rodent) and a number of birds that feed and drink at this site. In this sense, Castro (op. cit) observes that in relation to the Cerrado the "veredas" compare with oases. It was a frequent occurrence that, with the expansion of the agricultural areas in the Cerrado, many farmers did not respect the limits of the "veredas" and incorporated the channel zone into their cropped area (Figure 12). As a result, the frequent erosion in these sandy soils carries large amounts of sand, which invades the palm groves, killing (suffocating) this vegetation. This situation is aggravated by the high sand content and the slope of the soil. It can be seen that the topography is a transition between a lower part and a higher table-land ("Chapada"). All these factors favour erosion in this zone. Beside this, the watercourse becomes silted up. These situations can also be seen in Figures 13 and 14 in the Upper Taquari catchment.

17 http://www.geocities.com/RainForest/9507/fauna.htm - 08/04/02, 8:50. 18 The groves of Mauritius palms (family Palmaceae) besides other uses in the ecosystem, are important in photo-interpretation in the identification of "veredas" (Castro, 1980).

17

Figure 12. Area of "vereda" in the region of Guaratinga (MT), cleared and used as pasture, right up to the water channel.

Photo: Mario Friedländer Figure 13. Agua Limpa stream, near to its mouth on the small river Bom Sucesso. The stream bed is silted up due to a gully upstream.

Source: Padovani, C.R.� Embrapa Pantanal,2000. Figure 14. A sandbank in the channel, killing off a palm grove.

Source: Padovani,C.R.� Embrapa Pantanal,2000. At the present time, the "veredas" are protected by state law in MT (100 metres either side of the channel) but this is much less than the area required, which, according to Castro (op. cit) should be an 800m wide stripe an either side of the main channel. In fact, part of the cerrado in the envelope around the "vereda" should also be protected to guarantee the ecological sustainability of the "veredas". The protection is not only justified by the undoubted scenic beauty, but alos as a refuge for small rodents, birds, a diversity of micro-organisms which are present and also to conserve the water of this location. In terms of the location of the "veredas", they regulerly appear in the cerrado landscape of the Planalto, as, for example in the Serra de Petrovina in the municipalities of Pedra Preta (MT) and Alto Garças (MT). Camps with gilgai ("murunduns") The camps with "murundums" in the cerrado region show a characteristically high level of soil water. Vasconcelos (1998 in Silveira, 1998) points out that in Mato Grosso State, in the table-land region, this feature is related to the characteristic of the water sources, i.e., morpho-pedologic characteristics and to the hydrology regime. These area have typically little slope. All over the camp, small elevations occur - the murundums and part of the vegetation is differentiated. There is a site-specific presence of termites in most of the murundums, many of which have been partially destroyed by the action of armadilloes or ant-eaters, which, in so doing, contribute to the increase in the area of these mounds of earth (the murundums). Another feature of murundum camps is vegetation adapted to saturated soils (Eiten,1975; Oliveira Filho,1989; Vasconcelos,1998 em Silveira,1998). Silveira (op cit) in a study done in Campo Novo dos Parecis evidenced the presence of species with characteristics of those from wetlands such as Drosera sessilifolia, Polygala angulata, Syngonanthus specious, Xyris hymenachne e Eriocaulum gibbosum. Thus, the flora of these camps can be profoundly altered, or disappear, with drainage carried out for agricultural use of these areas.

18

One of the justifications for not using theses areas lies in the fact that laminar erosion would extend from the murundum sites, carrying off a fine layer of soil from the surrounding area, which would be sufficient to generate a change in vegetation, since the species are adapted to wetter areas. Besides, this constitutes a feeding area for ant-eaters, mammals which are threatened with extinction and agricultural use requires prior drainage. Since they present such site-specific characteristics, when compared to the rest of the system, the need for preservation of these areas is evident. Gallery forests, rocky areas and steep slopes As said earlier, it is necessary to preserve the areas around the headwaters of streams and water courses. This action is quite intuitive, but, in any case, it is necessary to explain the ecological role which the vegetation around these areas exercises. Besides the fixing of stream banks by the roots of the vegetation, these areas act as a filter for runoff (often carrying contaminants) from the higher areas. However, these are areas of rich bio-diversity, which can play the role of ecological corridors, if maintained along all the stream margins. The fragmentation of these forests transforms large extensions of natural habitats in numerous isolated islands, which contributes to the disappearance of various plant and animal species. In this manner, a very important aspect of the restoration, maintenance and management of the gallery forests is related with the diversity of tree species which contributes towards attracting and favouring the persistence of animal species19. Mato Grosso state, for example, has such a large drainage network, that if just these areas were preserved, there might not be such great preoccupation with the extinction of species. Rocky areas (outcrops, lithosols, regosols and cambisols) are rich in bio-diversity, and possess a vast genetic bank besides having vegetation specific to more rocky areas. These areas have the advantage of being steep and therefore have low potential for agriculture. Some of these areas are already being protected through, for example, the RPPN (natural reserve on private property) João Basso Ecological Park (S 16°35�40�� and W 54°35�40��), located near to the city of Rondonópolis (MT), with an area of 3,624 hectares. Figure 15 illustrates some rocky formations in the cerrado.

Besides this, the small mountain ranges and waterfalls in the BAP act as refuges for many rare or endemic species such as Harbenia gertii (exclusive to Serra da Petrovina), Urvillea paucidentata (a new species from Salto das Nuvens, in Rio Branco) Begônia aquidauanae (ornamental), Dykia spp. (camp and hillsides) e Gomphrena centrota (medicinal), among others (PCBAP,1997,p.33). Figure 15. RPPN João Basso Ecological Park - rock outrops in a protected área.

Source: Agropecuária Basso

Another phyto-physiogomy which appears in MT which should be possible to

preserve are the semi-decidouos seasonal forests. Theses appear on alluvial formations that are periodically flooded, such as in the Pantanal, By reason of having saturated soils during the flood season, they possess very specialised plant species. Also in these areas, Amazon species are found. In the BAP, this formation can be found along the Paraguay River and some of its tributaries (Ferreira, 2001). 19 Information available on the website: http://www.ibd.com.br/arquivos/artigos/matasciliares.htm

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4. Agricultural Chemicals and the Cerrado agro-ecosystem

Agricultural chemicals (ACs) or pesticides20 are also called "agrotoxics" in Brazil: insecticides, fungicides, herbicides, etc. These are crop protection chemicals which are on the environmental agenda since the results of their application began to appear. The ACs derive from intensive agriculture around the world, especially with cropping, which impoverished the agro-ecosystems, turning it more susceptible to the appearance of species injurious to crop plants. Amongst the undesirable consequences of the use of pesticides can be cited the presence of residues in the soil, water and atmosphere, in plant and animal tissues, the destruction of soil micro-organisms, mortality of insects beneficial to the equilibrium of the agro-ecosystem, prejudicial effects on non-target organisms, the presence of residues in/on food and, also, contamination in the workplace (Dores and Freire, 1999). In addition, insects, fungi and bacteria which are natural predators of other species, are affected, causing a complete imbalance in the agro-ecosystem. Because the total species number is reduced, they suffer alteration in their reproduction and behaviour, besides increasing their susceptibility to disease (who, 1980 cited in Dores and Freire, 1999). Another point is that the contaminated organisms can migrate, as, for example birds, taking these residues to distant parts, away from the site of origin. The synthetic organic compounds were developed during the Second World War, substituting plant-derived and inorganic and pesticides, the later being highly toxic to man and crops (heavy metals, such as arsenic, copper, etc.). Thus, DDT a synthetic organic compound was the first of this new generation accompanied by innumerous other chlorinated hydrocarbon insecticides and herbicides. Their widespread use has left an intensive legacy of contamination, since they are very persistent in the environment. This includes contamination of food products, which are bio-accumulated in the food chain, affecting principally the tissues of higher animals. Besides DDT, there are other pesticides which are highly prejudicial to the environment. These are called "Persistent Organic Pollutants" (POPs) of which there is a list of 12 highly persistent substances, persistent and toxic insecticides to the environment. Amongst these are 7 products, besides DDT: Aldrin, Endrin, Areidrin, Heptachlor, Mirex and Toxaphene. There are 2 industrial chemicals: hexachlorbenzene (HCB), also used as a fungicide and polychlorinated bi-phenyls (PCBs), used as insulating oil in electricity transformers. There are an additional by two products of the chemical decomposition of chlorinated compounds and also during the synthesis of certain herbicides. There are dioxins and furanes and are highly cancerigenous. Lindane (HCH), another highly persistent pesticide is not considered cancerigenous21. In Brazil, several of these pesticides here been banned since 1985. They had already been banned in the state of Rio Grande do Sul since 1982, as a result of having been detected in water supplies taken from the river Guaiba (Pinheiro, 1998). As a result of the expansion of Brazil's agricultural frontier, there has been a marked increase in the use of agricultural chemicals (pesticides) principally herbicides,

20 Amongst the non-target organisms there may be a diversity of bird, filth and wild animals which make up the ecosystem. 21 Lindane figures amongst the earliest second generation of pesticides, synthesized almost simultaneously with PDT, its use has also been prohibited in Brazil

20

in areas where Zero Tillage is practised. Besides this, new pests appear, showing genetic resistance to the products employed. Table 2, below, illustrates the growth of the use of agricultural chemicals in Brazil, analysed from the sales figures of 1988 to 1998. The use of herbicides shown in Graph 1 is analysed separately from the same data. Table 2. Agricultural chemical sales in Brazil (kg)

Class 1988 1991 1994 1998 Insecticides 256.897 222.007 300.246 581.693

Fungicides 183.215 147.112 211.080 436.235

Herbicides 506.224 533.591 775.762 1.368.723 Total 946.336 902.710 1.287.088 2.386.651

Source: Adapted from ANDEF, 2002

Graph 1 - A steep increase in the use of herbicides in ten years.

0

200.000

400.000

600.000

800.000

1.000.000

1.200.000

1.400.000

1988 1991 1994 1998

Herbicides

The crops in Brazil with the highest consumption of various groups of these

agricultural chemicals are soybeans, citrus, sugar cane, vegetables (potatoes and tomatoes) rice, cotton, cereals, coffee, maize and fruit (Paulino and Monteiro, 1997). 4.1 Elements/Processes that affect the dynamics of agricultural chemicals Agricultural chemicals in contact with soil or water may have three distinct destinations. They may be completely broken down, partially broken down, resulting in non-degradable metabolites or they may be only minimally altered, resulting in high persistence and accumulation of contaminants (Sethunathan and Alencar, 1998). There are various factors that influence the rate of breakdown of these substances. The intrinsic properties of agricultural chemicals (molecular structure, reactivity, concentration, volatility and others) and also the characteristics of the environment in which they are inserted. Thus, in order to examine the dynamics of ACs, no single element should be isolated but the interactions to which these products are subjected in the system should be studied.

21

There are many studies which demonstrate the importance of micro-organisms present in the soil (Monteiro, 1997; Arno, 2000; Frighetto, 1997), i.e., the function of the organic layer as a kind of soil filter, reducing the quantity of potential environmental contamination. However, the clay content, the p.H. and the cation exchange capacity should also be considered in studies of AC decomposition in the soil. When an agricultural chemical arrives in the soil, it partitions itself between the solid state, solution and gases (Glotfelty and Schomberg, 1989 and Monteiro, 1997). In this manner, what determines the change of the chemical from one state to another is the process of adsorption. This converts the chemical from mobile states (gaseous and liquid) to a stationary solid state. Adsorption is thus related to the mobility (see also p. 111). In practice, the greater the time the chemical remains in the soil (high adsorption) the greater the possibility of being decomposed without being transported to another environments through leaching or percolation. This reduces the risks of water contamination, for instance. However, it should be stressed that the chemical could be again liberated to the atmosphere. The two decisive characteristics in the process of adsorption are: the level of soil organic matter (SOM) and the solubility of the active ingredient in the pesticide. What effect can agricultural practices have on these components? As regards solubility, this depends on the inherent characteristics of the active ingredient of the AC; the quantity of soil/water present influences the adsorption of the molecules. In irrigated situation, where moisture is very high, the tendency is to reduce adsorption, leaching the chemical into the soil profile. With regard to SOM, soil management, the quantity of inputs applied, principally inorganic (manufactured) fertilisers has a direct effect on chemical adsorption. How does this happen? For example, through erosio, soil is lost and with it, the humic fraction of SOM. Another factor is soil compaction, caused by Conventional Tillage, as a result of the use of heavy equipment. Referring to inorganic fertilisers, an excessive amount reduces the quantity of soil micro-organisms, which favours the leaching of agricultural chemicals (ACs), in addition to eutriphication, as a result of excessive amounts of nitrogen and phosphate. Over-fertilisation inhibits the action of various micronutrients essential for plants. Even though natural factors are also responsible for alteration in the elements mentioned above, human interference is determinant in exacerbating the situation. Besides biological degradation of ACs, partial degradation may also occur through chemical or photosensitive processes (abiotic degradation processes), such as oxidation, reduction, hydrolysis and photolysis22. However, micro-biological activity is decisive in the complete breakdown of ACs. The diagram in Figure 16, below, shows the various entry points of ACs to the different "compartments" of soil and water as well as their degradation paths and their movement between the different environments.

22 For further information on abiotic degradation consult Fay, E., Silva, C., Melo, I. Degradação Abiótica de Xenobióticos. In: Microbiologia Ambiental. Jaguariúna(SP): Embrapa-CNPMA,1997,p.125 � 140.

22

Figure 16. Dynamics of the entry of pesticides into the environment and their paths of degradation.

Source: Dores e Freire, 1999, p.3.

Figure Translation

Pulverização: spraying Transporte de vapor e poeira: transport of gases and dust Precipitação: rainfall Aplicação direta no solo: direct soil application Fotólise: fotolisis Degradação biológica: biological degradation Volatilização: volatilisation Erosão e carreamento: Erosion and runoff Aplicação direta: direct application Efluentes industriais: Industrial effluents Esgotos municipais: Municipal sewage Lavagem de materiais usadas na aplicação: Cleansing of equipment used in application Solo: soil Absorção por organismos: adsorption by organisms Pesticida adsolvido: adsorbed pesticides Pesticida dessorvido: De-sorbed pesticide Água: water Decomposição química: Chemical decomposition Lixiviação: leaching Água subterrânea: Ground water

23

Observing this diagram it can be seen ACs can be transported with greater or lesser velocity within the soil or out of this ecosystem. The most common means of transport, or paths which are followed, in addition to adsorption (Dores and Freire, 1999) Monteiro, 1997) are:

• Volatilisation, co-vaporisation with water vapour, association with wind-carried particles - those bring the AC from the soil to the atmosphere;

• Leaching - the downward movement in the soil of ACs, dissolved or adsorbed to soil particles - this process is linked to groundwater contamination.

• Erosion - takes the AC along with soil particles; • Adsorption by plant root and/or by other living organisms; • Evaporation and transportation - these two processes affect the water held in the

soil and in plant tissues, taking with them dissolved substances. • Though soil macro-pores in conjunction with the downward movement of soil

water in channels opened by earthworms and other soil fauna, as well as in plant roots;

• Surface runoff - one of the principal processes for contamination of surface waters. Rainfall or irrigation water flows overland, transporting ions in solution or adsorbed to soil particles (Monteiro, 1997).

It should be emphasised that rainfall represents a return path for ACs, volatilised

direct into the atmosphere or through spray (or powder) drift23. Besides thi, some factors may influence the destiny of ACs in the environment and their capacity to reach their target with greater efficacy. Amongst the variables to be considered, Dores and Freire (1999) indicate three groups:

(a) Labelling: for use of the product includes consideration on the form of

application of the AC, the frequency and concentration with which it is applied and the disposal of used containers. The type of formulation is significant in relation to drift and leaching;

(b) The environmental characteristics of the location - those which have greatest effect are: climate, the physical and chemical properties of soil and water bodies, besides the local topography. As an illustration of this group of factors, Cohen (1995m in Dores and Freires, 1999) indicate that regions with more than 250mm, linked to a low soil water retention capacity, represent high probability of contamination of ground water. This description coincides with part of the study area, the Upper Paraguay river basin The annual precipitation is 1500mm and there is a predominance of sandy soils, especially in the upper Taquari basin, which are highly leachable.

(c) Physical chemical properties of the product - can influence the behaviour of the AC in the environment. These processes are detailed below with the processes which they influence.

23 Some Acs are in powder forma and when applied forma a cloud over the soil and this is called "derive".

24

Table 3. The relationship between physical/chemical properties of the active ingredient and the related process.

Physical/Chemical Process affected Solubility in water Leaching, degree of adsorption, mobility in

the environment and absorption by the plant Partition coefficient Potential bio-accumulation and adsorption

power of SOM Hydrolysis Persistence in the environment or in the biota Ionisation Pathway and mechanism of adsorption and

absorption persistence and interaction with other molecules

Vapour pressure Atmospheric mobility and velocity of vaporisation

Reactivity Metabolism, microbial degradation, fotochemistry and auto-chemistry

Source: Based on Madhun and Freed, 1990, presented by Frighetto, 1997. 4.2 Pesticides � Most frequent types and formulations.

The time an AC remains in the environment is called the "half-life" of the product (t 1/2). This is the time required for the active ingredient to reach 50% of its original concentration. "It is assumed that the remainder would not be noxious to the environment" (Matos and Silca, 1999, p. 112). The half-life is specific for each product and depends on the various factors already described. Some parameters are know and determine the time which each group of chemicals remains in the environment. Several authors cited by Alencar et al24 (1998, p. 11),state that the time to eliminate 75% to 100% of the residues can vary in accordance with the following diagram.

24 Hellawell, J. M., 1988; Kearny et al, 1969; Sethunathan, N., 1973.

25

Diagram 1 - Time to eliminate 75% to 100% of the residues

24 - 60months

chorinated hydrocarbon

4 - 30months

organo-chrorinated hydrocarbons

1 week- 3 months

organo-phosphato

inseticides

1 - 6months

Phenoxy, toluideneand nitrile derivatives

1 a 18months

Ureas, triazinesand picloran

Herbicides

Pesticides

Source: Alencar and all (1998)

26

Besides the chemical groups cited above, others commonly used as active ingredient are pyrethroids, carbonates and the nitroguanidines. These have a much shorter half-life than, for example, the chlorinated hydrocarbons. Amongst the herbicides, are the glycerine derivatives, which make up glyphosate (widely used as a desiccant in Zero Tillage)25. To the contrary of what is widely divulged to the public, the residual effect of this herbicide is not so short, being 30-90 days (Rodrigues, 1995). According to agricultural technicians of the study area26, herbicides are more persistent in the environment, being degraded slower than other types of ACs. One cannot forget that DDT and other PDP's, in general, as a result of their extreme stability, are present in various locations up to the present day, but the new insecticides tend to be degraded much more rapidly. Some organo-phosphorus compounds, for example, take 3 to 8 days to reach their half-life but are high toxic to warm-blooded (homothermic) animals. The most recent group of ACs on the market are the synthetic pyrethroids. In spite of their low toxicity to mammals and birds, they are highly toxic to cold-blooded (pecilothermic) animals, such as fish, amphibians, reptiles and also to beneficial insects (Pinheiro et al, 1999). With regard to the toxicological classification, tests are carried out to evaluate and classify the product in classes I to IV. This evaluation takes into account, the mode of action and toxicity (Lethal Dose - DL50) of the product. Laboratory tests expresses toxicity as mg/kg of live weight needed to kill 50% of the test animals. It is important to note that this express the degree of animal or human contamination and not that of the physical environment. From the above data, the product is classified in one of the four toxicological classes established by low (Gallo et al, 1988). These classes are represented by a colour code. The level of LD50 established for the respective classes are described in the table below.

Class I � extremely toxic Class III � moderately toxic

Class II - highly toxic Class IV � slightly toxic The types of formulation and the modes of application of ACs also affect the efficacity of hitting target organisms with the lowest possibility of dispersing into the environment. Formulations may be in liquid or solid (powder) form, in different gradation as follows:

Emulsified concentrate Liquids Concentrated solution as a paste

Concentrate in suspension Soluble powder

Solids Granulated forms Granules dispersed in water (GRDA)

1

25 On of the best know commercial names is "Roundup". 26 Interview with Paulo Lima, AC specialist in Primavera do Leste, MT state

Amongst these formulations, the powder form has the greatest capacity for dispersion, especially in the process of mixing it with water. It is at this moment that drift occurs and the (fine) powder can remain in the air, from whence it is deposited on the soil or water via rainfall. The future trend is for the containers to be fabricated of bio-degradable materials, e.g., starch (this is already the case with GRDA). This dispenses handling when mixing the product, since the container is placed directly in the water.

Application methods can be terrestrial (manual, tractor or self-propelled sprayers27) and aerial. Herbicides are applied mostly via tractor-pulled sprayers and both herbicides and fungicides, while insecticides and fungicides are mostly aerially applied. These methods of application refer to large farms and to the most important crops in the Cerrado bioma of the Centre-West; small farmers use backpack sprayers. With relation to greater dispersion in the environment, Frighetto (1997: p. 419) warns "aerial application can result in significant exposure of non-target organisms." In addition, the author comments on a number of studies which found that even under ideal conditions, only 50% the AC, aerially applied reach their target. It is necessary to take into account a series of factors, such as atmospheric pressure, direction and velocity of the wind and others. Amongst the biggest "villains" found in today's AC market, because of their high toxicity, especially to humans, are "Furadan", based on Carbofuran28, a seed treatment insecticide and 2,4-D, the active ingredient of a broadleaf herbicide. Specialists indicate that these products should shortly be taken off the market. Pinheiro et al (1999, p. 140) have made a vehement alert regarding the danger of contaminating the Pantanal and the Amazon - a region rich in water resources - by products based on Endosulfan, because this product is extremely toxic for fish and other aquatic organisms, even at very low dosage rates29. Another product which the author singles out for restriction on its use is Carbaryl, since this insecticide has the same toxicity level but for bees. The following table shows the most commonly used insecticides in soybeans, cotton, maize, rice and beans in the Cerrado region, the study area for this report.

27 A specialised sprayer used for application of agricultural chemicals 28 Carbofuran is the active ingredient derived from the Carbanate group of chemical, is the active ingredient, "Furadan" is the brand name 29 Pinheiro et al (1999) indicate that toxicity occurs at dosage rates lower than 0.01 pilogram, i.e., one billionth of a gram

2

Table 4. The principle insecticides used in soybeans, cotton, maize, rice and beans in the Cerrado region.

Chemical Group Active Principle

Toxicity characteristics and persistency on

environment Toxicity class

zetacypermethrin

Synthetic pyrethroids

lambdacyhalothrin

Only slightly toxic to mammals, causing possible skin lesions in humans. Extremely toxic to cold-blooded animals such as fish, amphibians, reptiles and also bees. No information on persistence in the environment.

Class II

Chlorinated hydrocarbons

(esters of sulphuric acid)

Endolsufan

Toxic to fish and aquatic organisms. The chlorinated hydrocarbons are extremely persistent in the environment and accumulate in the fatty tissue of animals, such that this insecticide does not show persistence in the environment.

Class I Class II

monocrotophos Class I

methamidophós Class II Organo-

phosphates Clorpyrifós

Organo-phosphates have a very short residual action, about 3-8 days, however most of these chemicals are extremely toxic to humans. Class II

Imidacloprid Thiametoxan Nitroguaridines Acetamiprid

No information Class IV

Tiouréias Diafentiuron No information No information

Carbonates Methomyl Moderate to high toxicity shown to rats under laboratory conditions

Class I

Carbamato sistêmico

Carbofuran (Furadan)

Very toxic to mammals and bees. Moderate toxicity to natural parasites and low toxicity to predators (tests carried out on coffee).

Class I

Source: Andrei, 1996. ; Galo, 1988. The corresponding tables on herbicides and fungicides are found in Annexes B and C.

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4.3 The dynamics of Agricultural Chemicals in water In a study carried out in the region of Piracicaba, SP state (Matos and Silva, 1999) showed that the danger of contamination of groundwater reserves is directly related to the quantity of organic carbon in the soil and its depth in relation to the water table. Organic carbon is linked to the soil's absorption capacity. The greater the absorption of the AC, the lesser the danger of reaching the groundwater. In soils with similar SOM contents, the half-life of the chemical. If it is not bound by the soil, the longer it takes to break down, the higher the chances of it reaching the groundwater. However, when ACs are washed into surface water, they may be simply dissolved in the water, or if they attach themselves to eroded particles transported as sediment or in particles settling on the stream bed, where they can still be absorbed by the organisms present. Hasset and Lee (In Dores and Freire, 1999) indicate that when ACs are absorbed in sediments, the probability of being broken down by micro-organisms is greater. It is therefore more advantageous for the environment, with lower chances of accumulation in warm-blooded animals, when the AC is adsorbed to soil particles. On the other hand, the AC may disengage from the sediment and be ingested by aquatic organisms, entering into the trophic chain. When rain occurs shortly after the application of an AC, there is a higher chance of the chemical reaching a water body in surface runoff. Figure 17 Dynamics of pesticides in the aquatic environment

Water Course

the food chain

Volatilisation Bio-accumulation in

Abiotic breakdown

Biological breakdown

Dissolved in water Adsorbed or digested by organisms

Adsorbed to sediments

Erosion/ Sediment transport

Surface runoffLeaching Rainfall

Agricultural chemicals

4

This diagram resumes the ways in which ACs can reach water bodies, how ACs

persist in the environment and the destination of the residues within the aquatic environment. Effect on the biota Non-target organisms are often seriously affected, even killed, by the action of ACs, principally by non-selective products30, Gallo et al (1998) refer to long-distance transport of ACs31 and also the significance for the ecosystem when they are adsorbed into biological systems. The author singles out two particularly important biological systems: effects on man and domestic animals and also on animals and plants in the wild.

The reliance of the microbiota should also be emphasised: it is frequently destroyed, making the agro-ecosystem even more vulnerable and inducing a higher utilisation of pesticides. Frighetto (1997, p. 420) gives the following modes of exposure of organisms to pesticide:

1. During pesticide application due to: - Exposure of the operator - Exposure to spray drift

2. Through crop foliage, due to: - Exposure by re-entry (transportation, evaporation, other) - Exposure via diet (ingestion)

3. Through the soil, from: - Exposure of the aquatic habitat - Exposure in drinking water (ingestion)

From this we can see that the exposure of living organisms, including man. besides being direct, through contact at the time of application, it also occurs indirectly via ingestion of food and though contamination of terrestrial and aquatic habitats. Frighetto (1997) states that the susceptibility of organisms is related to several factors, such as age, depth and stratification of the aquatic, and other, habitats.

The majority of poisonous substances attack the nervous system of animals.

After this sensibilization, the blockage of this system, even when temporary, causes irreversible damage. Other modes of action, in the ultimate case, also produce effects on the nervous system.

Many insects present resistance to the minimum efficient application rate for

their extermination. This process is a version of "natural selection", except that, in this case, the selection is artificial. The resistant individuals survive and give birth to new generations tolerant of the AC. Frighetto (1997) states that this does not signify the emergence of "super organisms," but simply of an altered genetic make-up, which enables it to tolerate a noxious substance. In a controlled experiment it has been 30 Non-selective chemicals are those which are non-specific in relation to target groups, killing or injuring organisms beneficial to the agro-ecosystem. 31 Traces of ACs have been found in Arctic species very far away from the point of application.

5

demonstrated that the increase in resistance was gradual, from one generation to the next, until it reached relatively stable permanent population (Gallo et al, 1988). The most important aspect of this question is that the number of resistant species in agro-ecosystems has increased annually and the economic losses incurred are considerable. Another causal effect is the increase in the use of mixtures if active ingredients, which increases the effect of the application, but without effective monitoring of the impacts on the environment (Pinheiro, 1999). Impact on Micro-organisms The soil micro-fauna includes single cell organism, such as bacteria, fungi and protozoa and invertebrates such as earthworms, molluscs, and an infinity of insects and others. This micro-fauna interacts directly with the plant species in the soil, forming a dynamic ecosystem with various ecological interactions. The nitrifying bacteria in the roots of legumes are an example of these reactions. When ACs enter in this dynamic system, there are a number of alterations, since both predators and prey are affected and, new chemical compounds are formed in this medium and the habitat is modified. Even though they may be temporary, they will disturb processes such as nutrition, metabolism and reproduction. The beneficial micro-organisms are affected by highly toxic ACs, principally those that are non-selective and when the target area is the soil32. However, there is another facet to this scenario, when the target organisms are more tolerant and the breakdown of the AC by micro-organisms is very rapid. Table 5. Some ACs and their effects on the micro-organisms of the soil.

PESTICIDES EFFECTS Simaziné (herbicide - maize) Increase in the population of aerobic N2

fixing bacteria Atrazine (herbicide - various crops) Reduction in the population of bacteria and

algae Trifuralin (herbicide - Soybeans) Reduction in the nodulation of legumes but

not in the bacterial population33. Captan (fungicide) Reduction in fungi and increase in

actmomyceteslyceles34 Source: Adapted from Frighetto (1997, p.423) Fish The nature of the effects of ACs on fish varies. Edwards (1973, p. 204) indicates that, besides causing death directly or indirectly through the destruction of food sources, fish show susceptibility through reduced growth rates and changes in reproductive behaviour, besides causing evident tissue damage. These indirect effects make the fish more susceptible to predators in their natural habitat, because they are less able to compete with normal fish. They are also less prepared to face stress situations, due to

32 Pre-emergent herbicides target the soil to kill creed seeds about to germinate. However, ACs, in general, are directed towards the aerial portions of the crop, there is a reduction in the efficiency of application (Frighetto, 1997). To illustrate this point, a number of ACs used in the Cerrado on the crops mentioned previously and their respective effects. 33 Rhibozia are nitrogen-fixing bacteria which inhabit nodules in the roots of legumes, e.g., soybeans. 34 Actinomycetes are

6

temperature changes and temporary food shortages, for example. This author also emphasises that, as a result of potential lethal effects of almost all ACs on fish, even in low concentration, it has become standard practice to carry out toxicological tests on aquatic populations. Tests of acute toxicity (LD50) determine the concentration which kills 50% of fish in the sample, within 24, 48 and 96 hours. The mode of entry of the chemical dissolved in water is via the gills of the fish. The majority of these tests are carried out in the USA on fish not common in Brazil, such as the rainbow trout (Salmo gairdneri), adapted to colder waters, the bluegill (Leponis macrochirus) to hotter waters (75o F). Butler (1965, in Edwards, 1973), based on several studies of the effects of ACs on fish and marine invertebrates, concluded that herbicide are less toxic to fish than insecticides. Referring to different fish sizes, the evidence points to greater susceptibility of fish fry to ACs than fish in less juvenile stages (same ref. 235) Alterations in reproduction can vary from mortality of fry, death of females, production of immature eggs and, finally, abortion. Pre-death behaviour may be affected by loss of swimming stability, respiratory difficulties and convulsions. In sub-lethal doses, even though the central nervous system be also affected, the alterations are not so drastic. However, especially with the chlorinated hydrocarbons, the cumulative effect can be lethal (Edward, 1973). It is important to state that not all pesticides are lethal or toxic to fish. Many of the current products break down very rapidly and water can contribute to their instability. Also, responsible agricultural practices, such as the use of correct AC application rates, normally do not result in the intoxication of fish. However, monitoring is necessary and studies need to be carried out to evaluate the new products on the market. It is also necessary to study the toxicology of the whole ecosystem and not just that of the fish, because they can be affected in different ways and by different elements of the system. Residues of chlorinated hydrocarbon chemicals and their breakdown products, are easily detected in bird tissue in almost every corner of the world. With a relatively small level of exposure, they accumulate in the fatty tissue. The principal residues are DDE, a derivative of DDT and Dieldrin, in lesser quantities (Edward, 1973). All the other chlorinates hydrocarbons have the capacity to bio-accumulate. As a result, birds of prey, which feed on other animals, such as fish, other birds and insects, tend to show a higher total residue content in their bodies, when compared to those which occupy the position of primary consumers, eating, for example seeds. One of the probable hypotheses of death for birds concerns the site of accumulation of residues. Research shows that if the deposition be greater in the cerebral region, the substance can be lethal, in comparison with other birds also with residue accumulation in other locations which had the same exposure but show sub-lethal symptoms. One of the principal consequences observed in some birds with the use of chlorinated hydrocarbons, especially DDT, was the reduction in eggshell thickness. The bird orders most affected in USA were Anseriformes (ducks), Falconiformes (hawks) and Strigiformes (owls). However, in other birds, such as quails and domestic chickens, moderate reductions in eggshell thickness were noted (Edwards, 1973).

7

Another pesticide cited as causing high avian mortality is Carbofuran (Flickinger et al, 1986 in Frighetto, 1997) in use to the present day. This insecticide appears of the ACs in the annexed list most utilised in the principal crops. The effects of chlorinated hydrocarbons on mammals are much smaller than in birds. Naturally, the predators higher up in the food chain will tend to accumulate more residues. However, the aquatic mammals are considerably affected. As for birds, the accumulation of toxic chemicals in the cerebrum is used as an indication of lethality. Annex D presents a table that illustrates the degree of toxicity of certain herbicides and insecticides used in the USA and Canada. These can serve as a basis for comparison for Brazil since some of those products are also used on the BAP. Waste generation is a notorious problem in the world, especially the question of dangerous residues which are encountered in some kinds of (toxic) wastes, as in the case of AC containers. The present legislation which covers this question - Decree no. 81.816 of 11.01.1990, chapter IV, Section III articles 45 to 48, although already amended, is very strict on the disposal of this kind of container. A triple washing process is mandatory, with the incorporation of this wash water in the tank mix to be used on the crop. According to the Environmental Protection Agency in the USA (EPA) 99.99% of the residues can be removed through triple washing (Alencar et al, 1998). The state legislation of Mato Grosso which covers this question35 is very emphatic on the treatment of container disposal. In this manner, in accordance with Article 1336 under no circumstance may these containers be buried in the soil, abandoned in the field, thrown out with domestic waste or burnt. Reutilization of containers is prohibited, except under authorisation from the competent authority. The washed containers are taken to the closest collection point. In general, these collection points are managed by partnerships between the local authority and associations or farmers' unions and are inspected by the Agricultural Sanitary Institute of Mato Grosso State (INDEA) and by the state environment agency. The reception of the used containers must follow the regulations related to washing. To the contrary, the containers are not accepted and must be subjected to a further washing process. In the ultimate case, when the containers are uncleanable, they are sent for incineration in special furnaces. The containers which conform to the regulations, after being collected at a central point are sent for re-cycling37. But it was not always so. Many used containers was thrown illegally into water courses, buried in a haphazard manner with no regard for protection of the soil, re-utilised as pots for plants or domestic utensils in the rural area or simply abandoned in the fields. Figure 18, bellow, shows an example which occurred in 1995 in the southern part of Mato Grosso state. Figure 18. Illegal disposal of Agricultural Chemical containers in a water course.

Source: INDEA files �Rondonópolis (MT), 2002.

35 Complementary law no. 038, dated 21/11/1995, amended by resolution nº 13 de 27/07/1999 (FEMA, 2002). 36 Resolution nº 13 de 27/07/1999. 37 These procedures are adopted in Mato Grosso state, but, in general, the other states follow the federal legislation, which is probably standard in all states.

8

From the picture it is apparent that, besides being in an inappropriate location, the label has a red band, which denotes the product's extremely high toxicity. Alencar et al, (1998) indicate that the residues inside an AC container can represent about 1% of their original content. The above scene indicates the total lack of information and/or awareness which reigned in rural Brazil a few years ago. Possibly, this situation still occurs in some places but the inspectors of the responsible government entity38 guarantee that these infractions are growing less day by day. According to the National Association for Plant Protection (ANDEF) the largest number of containers disposed of in the ten year period 1987-1997 was of plastic items39, followed by plastic bags, glass bottles and metal tins and drums. The data showing the total number of empty containers disposed of in this period, by type, are found in Annex E. Alencar at al (1998, p. 211) also call attention to the fact that it is not only containers which pose a threat to the environment. Leftover tank mix, wash water from sprayers, leftover ACs, outside the legal specifications and, also, products which have passed their use date. Dores et al (2002) report on the illegal disposal of DDT in the city of Cuiabá, capital state of Mato Grosso40, during the interval between its prohibition and being sent for mandatory incineration. 7 found a large spectrum of contamination, principally downwards in the soil, in spite of the low mobility of this chemical. This situation has a high possibility of being repeated in the many municipalities where such ACs were stocked. 4.4 A study of the use and impacts of Agricultural Chemicals in the Upper

Paraguay Basin The area dedicated to agricultural activities in the states which compose the BAP is large, generating the economic backbone of these states. Crop production is most significant in Mato Grosso (MT), although in the Upper Taquari basin in Mato Grosso do Sul (MS) crop production is also important. The area planted to the principal crops in these two states gives an idea of the quantity of ACs consumed. In MT, 4,026,200 hectares were planted on the crop year 2000/2001 of cotton, soybeans, rice and maize (main summer crops). There are also a number of products applied over a much wider area. Beside this, 19,642,000 head of cattle were produced mostly on extensive grazing, that occupy a large land area (FAMATO, 2002). Compared to data from 5 and 10 years ago,a steep increase in agriculture production is noted. The case of cotton is an example - increasing from 68,443 ha to 378,400 ha between crop years 1990/91 - 2000/2001 (Famato, 2002). The high consumption of ACs in cotton is well-known and this increase raises considerable concern with regard to consequences for the environment.

This picture has also generated considerable growth in the economies of MS and

MT states, especially the latter. The marketing of farm inputs has a direct relationship

38 Declaration received at the Regional Office of INDEA that inspects the southern region of Mato Grosso stare, composed of 17 municipalities 39 These are composed of the following types: high density poly-ethylene, co-extruded poly-ethylene and "tereftalato" poly-ethylene. 40 This product was used principally for the combat of malaria until 1997 when its use was prohibited (Dores at al, 2002)

9

with this picture. Below, Graph 2 illustrates the volume of this trade and, indirectly portrays the use of ACs in the states which comprise the BAP41.

Graph 2. Sales value (US$ '000) of insecticides, herbicides, and fungicides in MT and MS states.

1997 1998 1999

insecticides

herbicides

fungicides

insecticides 55250 101288 123981

herbicides 206482 276798 230635

fungicides 13148 25584 21177

1997 1998 1999

Attention should be drawn to the lack of research in monitoring the area of the

use of ACs, especially in the watercourses of the Upper Paraguay basin and other important river basins in the two states, MT and MS. Most research on AC residues is concentrated on the chlorinated hydrocarbons, with little information on direct contamination of water bodies. The principal constraint is the high cost of monitoring AC residues. The lack of financial interest in such as studies on the part of big companies , which monopolise the sales of these products in Brazil, should be noted. The responsibility for monitoring critical areas should be given priority by the state environmental agencies. Both states have laboratories equipped for residue analysis. In MS, this activity should shortly begin, but in MT there is a shortage of trained technicians. The most relevant work in this area in MT is carried out by the Chemistry Department of the Federal University of Mato Grosso, in Cuiabá.

Among the studies carried out in the municipalities of the BAP, there are a

number which point out the use of chlorinated hydrocarbons listed as POPs, even after their prohibition in Brazil (1985). In the crop years 1992/3 and 1993/4 the prohibited use of DDT and endosulfan was observed (a CHC which is still permitted) in the region of Cáceres, MT state, mixed in small proportions with other active ingredients in the cotton crop (Rieder, 1995 em Mazine,1997).

Another study demonstrating CHC residues on tomatoes sold in Cuiabá was

carried out between the years of 1996 and 1997. The most significant ACs detected were HCH (prohibited) with a 93% incidence and malathion (organo-phosphate) 76% incidence. In spite of this high incidence of detection most of the levels of both 41 it is convenient to state that the data represent the total of both states and not only the municipalities which comprises the Upper Paraguay basin.

10

insecticides were within the low category. The biggest residue levels were in tomatoes from São Paulo state42 (SP) (Vieira, 1998). This study sounds the alarm for monitoring this kind of residue in foodstuffs and, further for the need to monitor soil contamination in the production areas.

Further, due to the high persistence of the CHCs, principally the bio-

accumulation in fatty tissue,43 these residues were also detected in mothers' milk in 1996 in Cuiabá, MT in women at 3 - 4 days after birth. The results showed that 100% of the women sampled with new-born babies were contaminated with CHCs at an average level 2.34 times the External Residue Limit44 permitted by the WHO. The women from rural areas showed higher levels than urban women (Oliveira and Dores, 1998), which denotes a negative externality in agricultural occupations in this region.

Alves (1998) studied the contamination of sediments in the River Cuiabá in 15

samples distributed along its catchment. The insecticides investigated were Lindane, heptachlor, aldrin, endosulfan, endrin, P1P1 DDE and P1P1 DDT - all of the CHC group. DDT residues were found in two thirds of the samples. DDE residues in one third. As DDE is a breakdown product of DDT and the number of samples showing DDE residues was smaller the author concluded that DDT exposure in the region had been relatively recent. The author warned that, from this small number of samples, one should not generalise on the distribution of theses residues in the Rio Cuiabá catchment. The need for systematic monitoring is this reaffirmed.

In 1997, research was carried out in Primavera do Leste, MT - the divide

between the Upper Paraguay and the Araguaia Tocantins basins, with a large cropped area - an analysis of the ACs which presented potential risk situations for groundwater and surface water contamination in domestic water supplies45. The pesticides of ACs used in soybeans, maize and rice were analysed, also covered were small areas of tomatoes and grapes (Dores and Freire, 2001). Among the potential groundwater contaminants recommended for future study were the following active ingredients: methomil, maneb, triadimefon, atrazine, metribuzin, simazine, ethyl clorimuron, flumetsulan, fomesafen, glyphosate, imazaquim, imazetapir and metholachlor. Dores e Freire (2001, p.32) confirm that the most commonly encountered ACs in the context of groundwater contamination are: atrazine, metolachlor, simazine, metribuzin, and methonil. Annex F lists the ACs with high potential for groundwater contamination, derived from above.

Laabs et al (2001) also analysed the breakdown and leaching of 8 ACs used in

soybeans and maize in the region on a latosol near Cuiabá, MT. Those in the moderately leached category is found below 15 cm were: atrazine, simazine and metolachlor, measured 25 days after application. This demonstrates an important point: faster breakdown of ACs in tropical regions when compared to temperate ones. This is due to 42 The samples analyzed were from Goiás (GO), MT and SP states and taken from the principal open market and supermarkets (Vieira, 1998) 43 CHCs are only soluble in water and fatty tissue (lipo-soluble). They therefore accumulate in the tissue in higher animals and especially in man, which occupy the last link in the food chain. 44 65% das amostras apresentaram valores superiores a este (2,34). Além disso, o Aldrin, apesar de ter sido encontrado em somente três amostras ultrapassou 12,3 vezes o LRE. 45 Evaluations followed EPA recommended practice - water solubility, adsorption coefficient by SOM, Henry's low Constant, half-life in the soil and field conditions which favours percolation in the soil. Besides thi, the GUS score (vulnerability index for groundwater contamination was used.

11

the greater velocity of degradation and volatilisation in hotter climates. The high levels of solar radiation in the tropics also contributes significantly to AC breakdown through photolysis (Barceló & Hennion em Dores e Freire, 2001). Thus, since the half-life of ACs is, in general, determined in temperate climates, this question should be studied in tropical regions, such as the Upper Paraguay basin.

In the Upper Taquari Catchment (BAT), the use of ACs was classified and

quantified in a study covering the period 1985 - 1996 in São Gabriel do Oeste, MS. Soybeans came in first place in AC use, with triflurialin, a herbicide, the most utilised. Vieira et al (1999) emphasise that pre-emergent herbicide (PRE), when applied at above recommended rates can leave residues for up to 4 years. In addition, it is toxic to algae, even in single occurrences and, in continuous occurrenc, toxicity to fish also occurs, which can cause sub-lethal contamination.

A further relevant study was carried out by Riede et al, (1993-1997) on the

alteration in SOM on the fringes of the Upper Pantanal (Carceres, MT) in relation to the buffer effect which this exercises against AC contamination. They concluded that over the 12 years of soil cultivation and pastoral use in the study areas the SOM levels had depleted by 40-50% in relation to the natural state. The SOM has a large influence on the degree of adsorption of ACs in the soil, i.e., these chemicals are immobilised by the SOM particles which surround them. In spite of this, the authors alert that man's interference, to the extent that it weakens the natural buffer capacity of the soil, in conjunction with the ever greater introduction of pollutants, whose overall effects are still not well known, could provoke severe environmental risks for the fringes of the Pantanal and for the Lower Pantanal (same ref., p.107).

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5. Irrigated Agriculture in the Cerrado: policies, technology and impacts Irrigation goes back to the origins of humanity when man began to domesticate the first plants and their cultures in an environment whose climatic characteristics were inhospitable, where the rigours of the climate impede permanent agriculture. In order to make this possible, it was necessary to put back into soil the water that plants required. In this way arose the technology of irrigation, the only way to produce crops. As first, human and animal power was used to channel the water, which flowed by gravity in small canals to the cultivated areas. However, over a number of centuries irrigation methods remained unchanged with the industrial revolution, mechanical equipment substituted human on animal power. The new industrial paradigm was accompanied by significant development in technology, which contributed substantially towards established new methods and to the advancement of the science of agronomy, revolutionising irrigation. The second transformation phase in irrigation was the adoption of new technologies which permitted the more rational use of water. The high cost of the system, the water requirements of each crop and the efficiency of each method, the use of "ferti-irrigation46" and "ferti-irrigation47" were decisive in the rational use of resources (Santo, 2001: p. 58). The agricultural sector is the largest water use in the world and increased its consumption from 407 km3/yr in 1900 to 1996 km3/yr in 2000, corresponding to an increase of 4.9 times in one century (Setti et al, 2000: p. 54). In order to produce a ton of grain it requires almost a thousand tons of water, which explains the pressure exercised on water resources of the producing regions. The demand for agricultural products is equivalent to 70% of all surface and ground water diverted for use in the activities of modern society. The optimisation of the factors of production on a farm requires year-round production, independent of the rainy season. It is thus necessary to replenish the soil water with irrigation in order to cater for the plants' needs during periods when the water balance is unfavourable, as is the case in the Cerrado winter.

5.1 Public Policies for irrigation In the present day, irrigation is a common practice in many countries. Egypt irrigates 100% of its agriculture, Japan 63% and China 48%. In Brazil, in spite of an increase in irrigation, there is only a small area irrigated when compared to rainfed agriculture. (Genesio et al, 1990: p.111). Brazil has exceptional resources of water for irrigation; of the planet's total fresh water, 8% is found in Brazil. Irrigable areas total 30 million hectares of bottomlands, i.e., "varzeas" and 25 million hectares of other areas considered irrigable. According to Santo (2001: p 58) the area irrigated in Brazil was not expressive until 1960. The execution of the PROVARZEAS and PROFIR projects incorporated 1 million hectares of drained and/or levelled bottomlands, a 70% increase in the 1970's decade. 46 Application of fertilisers in irrigation water. 47 Application of agricultural chemicals in the irrigation water.

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In 1990, the total irrigated area in Brazil was equivalent to 2,7 million hectares, with 5% irrigates by furrow methods (an average of 3.2 Ha/farmer) and 67% with flood irrigation (an average of 13.7 ha/farmers). A further 28% is represented by drip and overhead irrigation (Garrido et al,1994:p. 200). In 1998, the total of irrigated lands had reached 2,870, 204 ha, not evolving from a similar figure at the beginning of this decade (Setti et al, 2001:p.63). The data permit the conclusion that the increase in area over this period was minimal. While new projects came on stream, old ones were abandoned and for this reason, the incorporation of new areas had little net incremental effect. The need to increase production for the internal market and to improve the participation of Brazil in the competitive international market, increasing productivity levels and improving the quality of rural life, stimulated the government to edit a new "National Policy for Irrigation and Drainage". This new phase is part of a process of public action which has been in force for 100 years (SRH/ MMA, 1968: p. 8) Over this long period, irrigation in Brazil received significant government participation, constituting four phases:

a) The first covers the period from 1875 to about 1965. Here, the federal government's presence was huge, but the actions were isolated, involving few crops and regions and even so the actions over time were discontinuous;

b) The second phase covered the end of the 1960', when the Group for Integrated Studies of irrigation and Drainage (GEIDA) was set up, which edited norms and regulations on a continuous manner up to the mid 1980's. From here emanated the concepts of the national programmes which characterised centralised planning of the military governments. Over this period general plans were implemented: in 1969 the PPI (Pluriannual Irrigation Plan) and in the 80's PROVARZEAS (The National Programme for Utilisation of Irrigated Bottomlands) and PROFIR (the Programme for Financing Irrigation Equipment). The latter two included the first initiative to include the private sector, including the allocation of "private sector lots" in government irrigation projects. The changes in the technology base for agriculture at the end of the 1970's decade, together with the federal government incentives to substitute imported goods destined for agriculture, stimulated the manufactures of agricultural equipment (Abreu, 1994: p.77). Thus, these programmes in the 1980's attenuated the agricultural credit crisis which was provoked by a lack of funding due to the economic crisis.

c) The third phase began with the New Republic, composed of two large programmes: PROINE (the Programme for Northeast Irrigation) and PRONI (the National Irrigation Plan) implemented from 1986 onwards. This distinguishes itself from the earlier phases by defining the role of the private sector. The government took responsibility for collective infra-structure support, notably in electricity supply and macro-drainage.48

d) The fourth phase began in 1995, when there was a re-orientation in irrigation policy. Within the list of proposals a greater role for the private sector was included in the development of irrigation and drainage projects, a consolidation of the irrigation equipment industry, an increase in the supply of agricultural products, with the possibility of year-round production, development of technologies and specialised cultivars for irrigated areas and, notably, training of technicians for irrigation projects.

48 Implantation of projects for the construction of a canal network.

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The change in the profile of Brazil's irrigation contributed to the fact that, during

the development of the National Policy for the Irrigation and Drainage Sector (NPID), these activities were considered as a business, covering various activities which required, as a basic condition, competence among the different actors involved. Even in the public irrigation projects, the new government orientation was the devolution of control to the water users. Irrigation ceased to be viewed just as an activity to resolve the difficulties ties of the semi-arid Northeast region and became a national activity.

The new Irrigation and Drainage policy was reformulated and oriented by four

factors, represented by economic feasibility, environmental sustainability (in accordance with the new Water Resource Law), the influence of globalisation on the market and, lastly, advances in technology and the potential to transform comparative advantages into competitive advantages (SRH/ MMA, 1998: p. 14).

The NPID defines geographical priorities, with a view to bringing certain areas

into the irrigation production process by consolidating "Axes of Development", a geographical directive of the Pluriannual Plan of the Federal Government (PPA). The concept of an axis of development brings new dynamism to regional growth. It does not present the characteristic of a pole of development because it acts as a vector which has its own field of force that attracts activities. This implies flows, economic connections and the integration of activities, where irrigation would be integrated as a fundamental link in the strengthening of the rural complexes of the region.

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5.2 Irrigation Methods In the modern era, there are three factors which are important to develop an irrigation project: an area with potential for irrigation, with favourable soil physical structure, good crop-growing conditions and water resources of good quality and in adequate supply. The choice of any method will then depend on topography, soil type, the shape and size of the land, installation and operation costs. There are several methods of irrigation:

• Surface or gravity methods: cover furrow irrigation, borders or flood irrigation where water is managed under gravity flow;

• Pressure systems: require water under pressure to operate. There are of three types: sprinkler irrigation, pressurised mechanically propelled systems and localised irrigation. The mechanically propelled systems are divided into centre-pivots and rain guns. The localised system is designed to place a small volume of water close to the stem of the plant. It is subdivided into drip irrigation and micro-sprinklers;

• Sub-irrigation: covers the application method which raises the groundwater table to close to the soil surface;

• Subsoil irrigation: this consists in subsoil drip system (Klar, 2000: p.55).

Below are shown in table 6 the different irrigation methods, with advantages and/or disadvantages for the environment.

Some determinant factors are in the choice of irrigation method, such as quality and quantity of the water and its costs. Depending on the type of crop and the choice of method the cost: benefit ratio can be improved.

5.3 Irrigation on the borders of Pantanal In spite of the extensive water network in MS and MT, the implementation of crop production activities presents a very important limiting factor: this is the characteristic climate of the cerrados, which has two defined seasons, one dry, the other rainy. Thus, crop production was initially concentrated in one half of the year, the wet season, which limited the economic exploitation of the land resource. With the introduction of irrigation, it was possible to open up new perspectives for the use of soil and water. This was the case, for example, in the intensive cropping areas located on the "planalto", on table-lands, coinciding with the best-drained soils of the Centre-West. According to the technical report published by the Interior Ministry (1974: p. 265), in 1970 irrigation in the BAP was limited to 1000ha of rice and horticulture crops, close to cities and hamlets. The major part of the crops, notably rice, was situated in areas subject to annual flooding; As a result, little was produced under the system of flood irrigation. The same study predicted that irrigation would be limited to green areas around cities, with profitable horticultural crops; little irrigation of field crops would occur.

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Table 6. Principal irrigation methods

Method Main systems Environmental advantage

Surface

● Furrows

● Flood irrigation

Evaporation losses are smaller due to the reduced area of water surface exposed. Thus, compaction risks in clayey soils are lessened, allowing the passage of implements as soon as irrigation stop ( Withers & Vipond,1977:p. 30). One necessary control is due to the presence of salts in the water or in the soil, which may form a superficial crust if the water covers the ridge49 wetting only the surface.

A low efficiency system with deep percolation losses and non-uniform water distribution over the irrigated area (Carvalho, 1995: p. 429). In spite of a possible efficiency of 50-60%, these systems implanted operate with efficiencies of 25-40%.

Pressurised

• Sprinkling

• Self-propelled systems

• Localised

The risks of affecting the structure and aeration of the soil are proportional to the water infiltration rate; the choice of lower application rates would be prudent. Low relative humidity also causes low efficiency, as do high temperatures and winds above 8 km/hr (Klar, 2000:p.59 ). In self-propelled rain guns the application rate is higher which could provoke the dis-aggregation of soil. In centre pivots, the application rate is lower but more energy is used. In low pressure pivots these may be runoff at the extreme towers, provoking erosion (Mantovani, 1998: p.58). There is a lower water consumption, because the evaporation from the surface is reduced and the water percolation is practically restricted to the crop root zone

Sub-irrigation

There is a lower less of water by evaporation, since it is supplied from below. Also this process may favour salinization.

Subsoil The consequences are similar to those of sub-

irrigation

49 The ridge between irrigation furrows.

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It appears that this study was wrong. However, with the knowledge then possessed by the technical community and the limits of state infra-structure, no alternative was foreseen for MT. The transformation at the end of 1970's and the technical breakthroughs in Cerrado agriculture, the division of the state into MS and MT and the development policy implemented by the federal government changed the course of history in the Cerrado of Mato Grosso. According to Embrapa's Department of Research and Studies (1987: p. 6), in 1981, at the irrigated area in Mato Grosso in which irrigation projects were designed by the state extension service (Emater do Mato Grosso) was 849 ha. In 1988 this had grown to 2,454 ha and there were estimates, also, of a further 4,500 ha of irrigated areas on farms not covered by Emater. Between 80% and 90% were irrigated lowlands ("varzeas") and 10-20% with conventional pipe-move sprinkling, with a minor area under furrow irrigation. In the 1985/86 agricultural year, the greatest area under irrigation was that of irrigated rice, with 8,219 ha, followed by horticultural crops with 4,251 ha and maize with 732 ha50. From the survey of the Master Plans for Irrigation for the Centre- West region, produced by the Ministry of the Interior in the beginning of the 80's, areas with aptitude for irrigation and drainage comprehended 30% of the state, totalling 264,300 km2 of these 95, 234 km2 corresponded to bottonland areas, estimated by PROVARZEAS. In 1987, the PRONI Programme allocated resources to the "Centrais Elétricas Mato-Grossenses" for the elaboration of studies the "Operation Plan for Irrigation and Electricity Supply", having its objective to put in place electricity systems to make irrigation viable and aiming at target areas of 31.551 ha in 1987 and 111.351 ha for the years 1988/90. However, in 4 years this target was increased by a factor of 3,5 (DEP/EMBRAPA, 1987:p.8). This study pointed out problems in the irrigated areas, such as the need to define crops for pivot irrigation and also rotation crops for this situation. It pointed up that "varzea" irrigation was showing the greatest number of problems, mainly, due to the large sizes of the irrigated areas. The greatest problems occurred with the large producers, affecting little the small producers. In all cases, the need for adapted cultivars was emphasised while iron toxicity and weed control were identified as problem areas which limited the development of irrigation. Government support for irrigated agriculture was restricted to investments in infra-structure and in technical support to the private sector through the PROVARZEAS and PROFIR programmes. The economic crisis which hit Brazil in the late '80s and during the '90s made it difficult to reach irrigation targets, due to the lack of financial resources. At the end of the '90s, the irrigation potential of the state of MT was insignificant when compared to the dimension of total cropped area of the state. The irrigated area in 1998 comprised 12,180 ha, corresponding to 0.42% of the country's irrigated area. Christofidis cited by Setti ( 2001:p.63) in an analysis of Brazil's irrigation sector identified MT as the lowest consumer of water for crops, using only 4,815 m3/ha/yr, or 65% of the national average, with an irrigation efficiency also of 65%, above the national average. 50 Amongst these the principal crops were lettuce (313 ha), squash (242 ha) and okra (226 ha).

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Of the total number of farm using irrigation in MT in 1996, 55% (574 farms) were located in the BAP. The largest concentration in the BAP was in the municipality of Rondonópolis (with 130 farms irrigated) in the catchments of the rivers São Lourenço and Itiquira, followed by the Cuiabá Micro region (110 farms) followed by Tangara da Serra ( 90 farms) on the Upper reaches of the Paraguay River (Annexe G) Careful attention to Annex G permits the inference that the largest number of irrigated farms in the Pantanal basin is not for grain production, but for horticultural and fruit crops in small and medium size holdings. It is worth emphasising that approximately 10% of the holdings in the Paraguay basin of MT are found on the lowlands, in the Cuibá depression and in the municipalities of the Pantanal, such as Barão de Melgaço and Poconé. This distribution can be explained due to the high concentration of population around the capital, favouring the transport of produce from small farms to supply the local vegetable/fruit market. Analysing those municipalities with the largest concentration of irrigated farms, Tangará da Serra, Rondonópolis and Jaciara stand out. In spite of these areas having many large grain and sugar cane producers, there is also a significant quantity of small and medium holdings that irrigate small areas of land and produce a diversity of crops. While in the decade of the 1980's flood irrigation predominated, at the town of the century systems had expanded considerably. The centre-pivot system jumped for 800 ha in 1980 in the whole of MT, to 4,000 ha just in the municipalities bordering the Pantanal, with 37 pivots in 2002 (Table 7). Table 7. Distribution of Centre Pivot Irrigation systens in the Upper Paraguay basin of Mato Grosso

State Municipality Area Area ( ha) Products Mato Grosso Alto Garças 01 NI NI

Cáceres 01 NI NI Campo Verde 07 680 NI Glória D�Oeste 01 50 NI Itiquira 09 NI NI Jaciara 02 NI NI Nobres 07 NI NI Pedra Preta 07 424 Coffee, phaseolus

beans Rondonópolis 02 140 Cotton, beans

* NI - No information Source: Agricultural technicians and municipal secretariats of agriculture The centre pivot was developed in 1952 in the USA and made possible the irrigation of large areas, more notably after the equipment was automatised. In the 1960's. this system imprinted a new dynamic in Brazil's irrigation. In the two year 1985/86 , the sale of pivots represented 48.8% of the irrigation systems sold in Brazil (Mantovani, 1988: p. 8). The centre pivot is the most appropriate method for irrigating in the Cerrado, for this reason it is the one most used for irrigation of grain crops, since economies of scale principally determine the profit margins in these crops (Silveira et al, 1999:p.7).

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In the spite of the small number of pivots in the BAP, in comparison to other areas in SP and GO, in recent years there has been a comparative regional increase in the regional scale51 of this system. There were three main factors for this expansion in the region: farmers who were capitalised and willing to adopt new technology plus the availability of water and technical assistance. The existence of this set of factors favours the possibility of the uptake of this system. Thus, from table 7, the role played by MT is emphasised, since it contains 80% of the pivots installed in the BAP, with the greatest concentration in the South of the state. Here are found the most capitalised farmers, pioneers of grain production in the Cerrado, with the municipalities of Campo Verde, Itiquira, Pedra Preta and Nobres making up 81% of the BAP total in pivots. In the catchments of the Itiquira/Correntes rivers is found one of the focal points of grain production in MT, concentrating in this region the largest number of pivots in the BAP. These rivers will shortly be utilised to generate electricity, which presupposes a regular flow in the channel. Thus, future use of water for irrigation will be limited by this factor, creating a conflict between agricultural use and that for electricity generation. An identical situation occurs in Primavera do Leste, in the watershed between the Araguaia basin and the BAP where the concentration of 53 centre-pivots in the municipality is causing conflicts. To reduce the consequences of these, an Association of Irrigators was formed, which, jointly with the prefecture, had a detailed study done for certain water courses with a view to establishing parameters of extraction in order to regulate or impede the installation of new pivots52. An empirical value of 30% of the minimum flow in September was established as the upper extraction limit for the totality of the pivots on any stretch of a water course. However, the Secretariat of Water Resources of the MT Environment Foundation is developing a norm where this limit would be 10% of the minimum stream flow53. If this law comes into force, it will provoke conflicts within the BAP and on its borders. Other overhead irrigation systems which evolved significantly were the self-propelled rain guns, especially in the sugar cane crop. Destined to supply the sugar mills and alcohol distilleries of MS and MT54, these systems are used for ferti-irrigation with the sugar mill sludge as a biological fertiliser. Although this is not adopted on the whole of the sugar cane area, it probably occurs on some 5% of the area cropped55. The availability of water resources in Mato Grosso do Sul state is also significant. The state is almost totally encompassed by the BAP, with 51.6% of the study area (177,167 Km2 ) and 49.3% in the Paraná River basin (or 173,093 Km2) and

51 The perspectives are for significant growth, to such an extent that one of the largest pivot manufacturers in the country plans to install a factory in Cuiabá by 2004. 52 Damming the streams for irrigation purposes is not permitted in MT, only direct extraction by pumping is permitted. 53 It was not possible to obtain in the literature or in the government departments responsible for the environment any regulatory parameters which would permit the establishments of scientifically-derived upper limits for water extraction from rivers that would not affect the aquatic ecosystem 54 Within the BAP, there are 5 sugar mills and one distillery in MT and three distilleries in MS. 55 Information from technical personnel employed in agriculture.

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0.1% of the state (288 Km2) in the Tocantins/Araguaia basin, according to the Department of Studies and Research of Embrapa (1987:p.20). In the year 1985/86, the crops with the largest irrigated area in the state were paddy rice on 8,500 ha in wet bottomlands (váezeas) and sprinkler-irrigated wheat on 8,500 ha in Fazenda Itamarati. Other areas were located on the surrounding planalto, with other crops also sprinkler-irrigated. The study carried out for the Irrigation Master Plan for the Centre-West region concluded that 60% of the area of the state (210,329 km2) showed aptitude for irrigation or drainage. According to the Department of Studies and Research of Embrapa (1997: p. 23) the analysis carried out by EDIBAP (Integrated Development Studies for the BAP) attested that in the MS portion of the basin there were the equivalent of 500,000 ha apt for irrigation which this study indicated as having the possibility of exploitation with "no-alteration of the existing ecosystem". This analysis was carried out without taking into consideration the implications for the water resources and the environmental modifications suffered by the land, because the environmental legislation was only drafted at the time of the study. In 1986, there were 40,000 ha irrigates in MS, with 70% of these under flood irrigation and 30% with overhead and furrow irrigation. Under centre pivots systems there were 9,000 ha and with piper-move sprinklers and furrows there were 3,000 ha (DEP, Embrapa, 1987: p. 30). Mato Grosso do Sul irrigated 61,400 ha in 1998, equivalent to 2.1% of the irrigated area in Brazil. The consumptive use of water by crops is one of the lowest in the country, involving 4,935 m3/ha/yr, corresponding to 67% of the average consumptive use in Brazil, with irrigation efficiency reaching 60%, slightly lower than the national average (Setti, 2001: p. 63). The analysis in Annex H demonstrates how irrigated areas ware distributed in the Pantanal basin. The first situation which stands out is the excessive concentration of holdings with irrigation in the micro-region of Campo Grande and within this, the role of the municipality of Campo Grande. From the Agricultural Census of 1995/96, the municipality of the state capital has 30% of all irrigated holdings in the state of MS and in the BAP. Considering all the municipalities in the micro-region of Campo Grande, the proportion rises to 70% of the irrigated holdings in the BAP, i.e., nearly 3/4 of the total are in this micro-region. The same situation as in MT repeats itself. The municipalities contiguous with the state capital concentrate a high number of small irrigation systems, almost always geared to the production of vegetables and fruit to supply the largest concentration of population in the state. While in MT 79% of the irrigated area is in the interior of the state, in MS this figure represents only 29%.Taking the two states together, the micro-regions which contain the state capitals have 55% of all irrigated farms in the Pantanal basin.

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In the state of MS, the State Secretariat for Production's data for 1996/2000 show that only 2% of the state's irrigation systems is in the Pantanal basin. In this basin, the most important grain-growing area is the municipality of São Gabriel do Oeste, which concentrates 67% of the pivots (table 8). Table 8. Distribution of centre-pivot irrigation systems in the MS portion of BAP.

State Municipality No. of Pivots Área ( ha) Crops Mato Grosso

do Sul Campo Grande 01 16 Horticulture

Costa Rica 02 180 Irrigated pasture, maize and beans

São Gabriel do Oeste 06 610 Beans and maize

Source: Agricultural officers of Municipal Agriculture Secretariats. The perspectives are for an increase in the centre-pivot-irrigated area in the Northeast of MS, especially in the micro-region of Alto Taquari and in the municipalities bordering Goiás state (GO) and MT, which are influenced by the construction of the Ferronorte railway. However, there are limitations in certain areas due to the low number of water courses on the table-lands.

5.4 Potential impacts of irrigation The technical report of the national Department for Public Works and Drainage - DNOS/MINTER (1974:p.267) warned about the extraction of water at a time when part of the ecosystems of Mato Grosso (before division into two states) were under preservation. DNOS alerted that water use for irrigation should be restricted to the minimum possible for each crop, not adopting, under any circumstances, irrigation systems which implied wasteful usage. While this study at the beginning of the 70's alerted the readers to the risks of irrigation, others in the 80's did not preoccupy themselves with this aspect. In the technical report of DNOS, alterations had been detected in the BAP. The drying out of the soil over the length of the basin had been observed by specialists and the population at large. On the planalto, the death of a number of "plant associations" occurred; in the lowlands, the expansion of the cerrado vegetation could have been an indicator of this drying out, or even its cause. This vegetation type substitutes others when the groundwater table drops to a greater depth. The report referred to made an analysis of the environment, unaltered by a predatory agriculture in the region at the end of the '70's. The technologies which evolved in the agriculture of the developed countries cannot be simply transferred to tropical countries without restrictions. The "failure of these undertakings, which included the establishment of irrigated agriculture is linked to the lack of a broader vision, which should include the existing relationships between productivity and stability of the tropical ecosystems and (the problems of) misplaced applications of existing technologies" (Lima et al, 1996: p.428).

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In spite of the fact that since 23/01/1986, Brazilian environmental legislation had defined criteria for allocating responsibility and the need for prior studies of environmental impact, only in 1992 did IBAMA elaborate a document establishing norms for irrigation projects. During the 1980-90 decade, the time of large irrigation projects, irrigation was carried out freely, without being disciplined by the authorities of the environment. The intensive occupation of the watersheds of the river basins, to which locations the irrigation projects had migrated, changed the paradigm for soil use in the region. Surface irrigation methods were gradually replaced by other methods. Soils which are immersed by flood irrigation suffer alterations induced by anaerobic conditions, causing the chemical compounds to release their oxygen. The soil texture characteristics and crop cultivation methods are determining factors in the development of an anaerobic layer which, may extend depths of 20 to 75 cm, showing greater intensity in sandy soils (Primavesi, 1997: p. 435). Nitrogenous compounds of iron and manganese and free iron are leached through the un-weathered profile56, forming manganese-iron concentrations concretions which forma hardened and resistance layer which impedes the penetration of water. This process does not occur in alkaline soils and in soils low in manganese and iron. This reduced layer has a negative effect on crops, such as irrigated rice, reducing yields over time. The alternative consists in periodically planting a dryland crop after two years of flooded cropping, when the organic matter should be incorporated into the surface and the reduced layer destroyed. Soil conservation is a permanent preoccupation in irrigated areas because inadequate management can cause the formation of surface caps and affect the soi's bio-diversity57. Amongst the systems of irrigation, the most aggressive to the bio-structure is irrigation by flooding, followed by overhead irrigation, furrows (infiltration) and subsoil irrigation (Primavesi, 1997: p. 449). The bottomlands ("varzeas") irrigated by any method, suffer an elevation of the water table and over-irrigation brings potential salinisation (Klar, 2000: p. 74 ). The occupation of the bottomlands and utilisation for agriculture in the '80s' was one of the factors in the degradation of this environment. The bottomlands constitute the flood plains of the water courses and are susceptible to periodic flooding. The cropping of these areas entrains other impacts as a result of the intensive use of land, which can contaminate the flow channel with chemical residues from the cropped area. During periods of flooding, there is a rise of the transport of dispersed soil particles, increasing the sediment load in the river beds. At present, this is a process of small magnitude, due to the limited area so occupied by virtue of economic considerations and the environmental laws. Another problem with irrigation is the process of salinisation. its occurrence is a direct consequence of the relationship between, infiltration and evaporation. When infiltration is more intensive than evaporation, the salts are leached and the soil is acidified. Inversely, when evaporation predominates, the salts are deposited at the soil surface, causing salinisation (Primavesi, 1977: p. 440). According to soil type, the

56 Material derived from the decomposition of the rocks of the earth's surface. 57 That structure derived from the action of soil micro-organism on soil organic matter (SOM).

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dynamics of salinisation vary. Thus, clayey soils are more liable to greater upward movement of water in the soil. In arid and semi-arid regions, the effects of salinisation are more intense, in spite of its occurrence in soils which have a lower salt content. As a result of the lower and more concentrated rainfall in arid areas, there is not a constant replenishment of soil water. For this reason, the predominant direction of soil water movement is upwards, producing a concentration of salts at the surface. The speed at which salinisation occurs is affected by compaction and increased soil density which reduce water infiltration and at the same time increase crop transpiration due to reduced oxygen levels in the soil. Besides this, the negative effects on the soil are more evident in areas of poor drainage. The process is especially accentuated with furrow irrigation. Cavalcanti cited by Silva Filho (2000: p. 114) states that, irrespective of water quality and the method of irrigation, there is a risk of provoking salinisation and alkalinisation of the land. If irrigation is practiced with saline water, without the necessary precautions and with deficient drainage, there is an accumulation of 10-20 tons salt/ha/yr, sterilising the soil irreversibly (Klar, 2000: p. 70). In the semi-arid region of Brazil, the problem assumes a certain significance with salinisation by sodium carbonate, but in the Centre-West (and in MT especially) if is little seen. There are some localised areas of saline soil in the BAP, present at points in the Pantanal which are not utilised for crop production and therefore offer few risks of the occurrence of this common problem in irrigated areas. In the areas on the fringe of the Pantanal, under centre pivots, impermeability is not common. First, because latosols are well-drained soils, constituting the largest soil group where intensive agriculture is practised; second, because the centre-west farmers have the highest technical/economical management capacity, they understand that compacted soils can lead to salinisation. They have competent technical assistance, carry out proper soil preparation and use the required cropping practices. It thus appears that, up to the present moment, the irrigated areas in the BAPP do not suffer from any soil degradation problems. The system of micro-sprinklers allows salt accumulation around the nozzle, which can be leached by rain water, transporting the salts to the plant root zone (Klar, 200: p. 66). During the operation of an irrigation system, several activities can be incorporated. One of these is "chemigation" which allows the application of agricultural chemicals with the irrigation water. However, the water distribution of any overhead sprinkler system will depend on the plant cover. According to Conte and Leopoldo, cited by Mundim & Follegatti (1997: p.295), "water losses" from interception by plant cover should be taken into account for sprinkler-irrigates annual crops, since the plants interfere with the coefficient of uniformity and irrigation efficiency, modifying then according to the crops, interception of the irrigation water will depend on the age and type of crop.

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When chemigation is directed at the soil, an analysis of crop interference is fundamental. The stage of crop development may favour or impede the application and provoke changes in the spatial distribution of the water. In gramineous crops, the leaf formation reduces water infiltration as a result of the leaf geometry in relation to the stem, which favours water retention, as in the case of maize and sugar cane. In the planning of a sprinkler irrigation system, the factors which impede a uniform distribution of water should be carefully studied especially in the case of applying agricultural chemicals. An excess of water around the stem, channels the product to the root, facilitating leaching of the applied products, with both economic and environmental costs. Mundim & Folegatti (1997:p.304) recommend that, if the objective is to apply the product close to the stem, in a gramineous crop, the application rate should be reduced. If the objective is to hit the middle of the interrow58 the application rate should be increased, in order to, compensate the losses from leaf retention and later channelling to the stem. The soils of the centre-west table-lands have excellent physical characteristics for agriculture, in spite of their low fertility. Most of these soils are latosols, with high permeability, no stones and a thick intemperised layer. This favours agricultural development but, on the other hand contributes to environmental degradation because it favours the leaching of micro-nutrients and chemicals applied to the topsoil. In an experiment of Vieira (2000: p. 150)) it was demonstrated that, in over-designed irrigation projects or those under bad management, the "utilisation of insecticides, both in seed treatment and through chemigation, under these circumstances may represent a serious threat of groundwater contamination when the soil buffer capacity is low or the pesticide is highly soluble in water." These risks are omnipresent and it falls to the farmers to understand the operating details of their equipment and to train their work force to avoid, or minimise, these impacts. Today, a considerable number of centre pivots utilises the Zero Tillage technology, implying greater utilisation of herbicides. According to Caetano et al (1995: p. 29) the adsorption of these agricultural chemicals in the soil layers depends on their physico-chemical properties59. The adsorption is affected by the type of soil structure and composition of the soil, where the greater presence of clay and organic matter favours adsorption. In the "centre pivot system the mechanised operations and the intensive use of agricultural chemicals can potentialise adverse impacts on the quality and availability of water resources" (Ferreira et al, 1996: p. 468). Among the effects of this alterations in re-cycling of the principal nutrients and carbon, as well as the displacement soil particles and dissolves chemicals to aquatic systems. Besides, the above problems, electricity supply also represents a limitation. It is the principal energy source for irrigation equipment creating a growing demand and requiring heavy investments in generation capacity and distribution. The expansion of the pressurised irrigation systems in the '80s was made possible because the state

58 The area between two crops rows. 59 Adsorption is the process by which a substance adheres to the surface of a clay particle.

25

invested in the expansion of the electricity network in the agricultural regions, accompanied by loans for the installation of irrigation systems. In order to complete a full turn a centre pivot takes an average 21 hours. Special use electricity tariff covers only a part of the time the equipment is used (Santo, 2001: p. 59). The energy consumed by a 60 hectare pivot is equivalent to 79 km per hectare/how. The cost is high, rising to 22% of the variable cost of maize production. Good water management is important because plants must have the right quality of water, avoiding excessive consumption of water and waster of electricity. The infiltration rate of water into the soil, the water use requirement of each crop and its root system development are important variables in the management of irrigation. (Mantovani, 1998: p. 63). The higher demand for irrigation water in the dry season should be emphasised, when soil moisture is reduced, the water table drops slightly and the streamflows are reduced. It is exactly at this time that the demand for irrigation water increases in direct proportion to the conflicts over its use. In the atypical year for 2001, operational difficulties were observed in overhead irrigation systems in some parts of MT, due to restrictions on the consumption of electricity and the prolonged period without rain in the proceeding year, when total rainfall was below average, some centre-pivots had problems to obtain an additional supply of water. When irrigation is correctly carried out, it permits an expansion of the cropped area, increases yields and improves farm incomes. However, non-observance of certain norms, principally, those related to the environment can transform the "largest capital asset" of the farmer - the soil - into an inert space devoid of life.

26

Index of Agricultural chemicals Annexes Annexe A: Toxicological classification of insecticides Annexe B: List of fungicides (chemical group and active ingredient) most-used for

soybeans, maize, cotton, rice and beans in the BAP area Annexe C: List of fungicides most used in the Upper Paraguay basin in the principal

crops. Annexe D: Toxicity of some herbicides and insecticides used in Canada and USA Annexe E: Survey of different types of agricultural chemical containers for the period

1987 to 1997 Annexe F: Principal active compounds with high surface water contamination potential

in Primavera do Leste, MT in 1997 Annexe G: Number of irrigated farms in the Upper Paraguay basin in MT -1995/1996 Annexe H: Quantidade de Estabelecimentos Agropecuários com Irrigação na Bacia do

Paraguai no Mato Grosso do Sul � 1995/96.

27

Annexe A

Toxicological classification of insecticides

Classification

DL 50 Oral (mg/kg)

Provable lethal dose for an adult

Extremely toxic 5 A few drops Highly toxic 5 � 50 A few drops to one teaspoon Moderately toxic 50 � 500 1 teaspoon to 2 soup spoons Low toxic 500 � 5.000 2 soup spoons to two cups Slightly toxic 5.000 2 cups to 1 litre Source: Adapted from Gallo, 1988, p.310

28

Annexe B

List of fungicides (chemical group and active ingredient) most-used for soybeans, maize, cotton, rice and beans in the BAP area

Chemical group Active ingredient Benzimidazol Carbedazin Estrobirulinas Azoxtstrobin Ditiocarbanato mancozeb Benzotiazol tricyclazole

29

Annexe C

List of fungicides most used in the Upper Paraguay basin in the principal crops

List of most used herbicides in soybeans, cotton, maize, rice and bean on the Cerrado region.

Product (active

ingredient)

General characteristics (chemical groups and use category)

Adsorption and leaching

Degradation Photodecomp. and volatilisation

Persistence* in the soil

Toxicity to wild life Toxicology class

Glyphosate Derivative of glycine, non-selective post-emergent used in Zero Tillage.

High soil adsorpition, little leached

Microbial activity with half life (t ½) 28 days.

Insignificant 30 - 90 days Toxic to birds (quail) and mammals (dogs). Not toxic to fish or bees

Class IV

Paraquat Derivative of the bipyrgridines with instantaneous absorption by plants, used in Zero Tilage.

Complete adsorpiton on contact with soil. Zero leaching

Very slow via microbial activity

Only sensitive to photolysis on dead plant tissue

Long, but with no movement to adjacent areas

Mammals (dogs), birds (chickens), fish (Resbora heteromorpha)

Class I

Chlorimuron-Ethyl

Derivative of the sullfoniated-ureas, used to control broad-leaned60 weeds in soybean. Post-emergent

Moderate. Greater mobility in the sandy soils

Initially chemical hydrolysis followed by microbial action

Insignificant t1/2 is 7-5 weeks. Low in sandy soils and hot climates.

Birds (ducks); fish (trout); bees

Class III

Imazethapyr Derived from the imidazolinones, early post-emergent on soybeans weeds

Colloids; resistant to leaching

Slow, via aerobic microbial action

Low Not available Acute toxicity for rats and rabbits

Class IV

Lactofen Derived from di-phenyl etters, controls annual broad-leaned weeds in pre and post-emergence.

Strongly adsorbed by the soil colloids; resistant to leaching

Principally microbial

Low volatilisation 4-6 weeks when applied as a pre-emergent

Acute toxicity for rats and rabbits

Class I

60 Broad-leane dplants are named dicotyledons and narrowed ones are named monocotyledons.

31

Product (active

ingredient)

General characteristics (chemical groups and use category)

Adsorption and leaching

Degradation Photodecomp. and volatilisation

Persistence* in the soil

Toxicity to wild life Toxicology class

Haloxyfop-methyl

Derived from the group of the oxy-fenoxy-propinates; post-emergent to control grass weeds in soybeans.

In light soils, under high rainfall some leaching may occur

Hydrokysed to haloxyfop acid, the active form of the product

t½ life is 13.4 days Halopxyfop acid has t1/2 of 55 days, on average

Low for birds (quail) and high for fish (trout)

Class I

Alachlor Derivative of the aceto-anilidines used to combat broad-leaved weeds and some grass weeds � pre-emergent.

Little leached Principally microbial

Insignificant 6-10 weeksvarying with soil type and climate. Does not move to neigbouring areas.

Birds (trouts). Not toxic to bees

Class I

Clomazone Derivative of the isoxy-azolidinones controlling annual grasses, pre-emergent for weeds.

Adsorbed by the soil colloids with low to medium leaching in sandier soils low in SOM

Microbial under aerobic and anaerobic conditions. Also degrades chemically

Minimum T1/2 de15 a 40 dias

Birds (wild duck); fish (trout); bees (no information)

Class II

Diuron Derived from urea. Used generally as a pre and post-emergent, mixed with other residual herbicides

Little leached in clay soils and heavily leached in sandy ones, being able to reach roots of the crop

Principally microbial

Sensitive to photo-decomposition and moderately volatile

4-8 months. Very high discs can provoke fitotoxicity for several years

Birds (Japanese quail), fish (trout). And non-toxic to bees.

Class II

Atrazine Derivative of triazines; selective pre and post-emergent herbicide

Adsorpition efficiency proportional to the SOM content. Little leached. Not found below 30m. depth

Principally microbial but also chemical and physical

Sensitive to photolysis and only slightly volatilisation

5-7 months. Soil sterilant with persistence greater than 12months

Birds (quail), fish (trout); bees (non-toxic)

Class III

Bentazon Derived from the thio-diazines, post-emergent for broad leaned weeds.

High adsorbed. Leaching is slow due to high adsorption and by rapid degradation of

Essentially microbial

Not sensitive Low. 2-5 weeks. 4 days after application of 4 ton/ha, no residues are detactable

Birds (wild duck), fish (trout); bees (non-toxic)

Class II

32

the products; Product (active

ingredient)

General characteristics (chemical groups and use category)

Adsorption and leaching

Degradation Photodecomp. and volatilisation

Persistence* in the soil

Toxicity to wild life Toxicology class

Trifluralin Derided from di-nitroanilines61; pre-mergent controlling annual and perennial grasses and some broad-leaned weeds.

Strongly adsorbed in soils with high SOM. Leaching and lateral movement sloe, but does occur.

Chemical and microbial principally in anaerobic conditions and by photolysis

Vary sensitive to photolysis, making soil incorporation necessary to avoid high losses of products

Medium persistence; after 180 days 1.8 ppm of residue was detected in soil. Moves laterally

Birds (chicken) � low toxic Fish (trout) - toxic Bees - non-toxic

Class II

2,4 - D62 A fenoxy-acetic acid derivative. It is a systemic herbicide controlling broad-leaned annuals and some perennial weeds applied pre-planting and incorporated a pre and post-emergence

Higher adsorption in clayey soils rich in SOM. The amine form of the product is more soluble than the ester form which is lees soluble and mobile

Microbial breakdown produces succimic and acetic acids.

Not very sensitive photolysis. Volatilisation is higher in the ester form than in the amine.

In clayey soils and hot climates residues dual activity does not exceed 4 weeks. In day, cold soils decomposition is much slower

Birds - moderately toxic Fish - toxic Bees - non-toxic

Class I

* Permanence in the soil is very related to the quantity of organic matter and the consequent microbial activity.

61 Also in this group is found Pendamethalin, a pré-emergent herbicide whose commercial name is Herbadoxi; it persists in the soil for 306 months and is not easely leached. 62 The greatest criticism that this agricultural chemical suffer is that it is for its high toxicity, principally for homeothermic animals amongst them, men.

33

Annexe D

Toxicity of some herbicides and insecticides used in Canada and USA

Active oral toxicity LD50 (mg Kg �1)

Herbicides* Insecticides*

Toxicity in birds Practically non-toxic (>2000)

Atrazine, butilate, 2,4 D, methyl-diclofop,EPTC, glyphosate,metaloclor, triallate, trifuralin

Carbaryl, benzene hexaclorate (lindane)

Slightly toxic (500 � 2000)

Alaclor,MCPA** Malathion

Moderately toxic (51 a 500)

Cianazine Methyl-azinphos

Highly toxic ((10 � 50)

Bromoxynil Clorpirifos,fonofos, terbufos dimethoate

Extremely toxic (<10)

Carbofuran

Toxicity in animals Practically non-toxic (>2000)

Butylate, EPTC, glyphosate, metholaclor, trifuralin

Malathion

Slightly toxic (500 � 2000)

Alaclor, atrazine, methyl-diclofop, MCPA, pendimethalin, triallate

Carbaryl, dimethoate

Moderately toxic (51 a 500)

Bromoxynil, cianazine, 2,4 D, difenzoquat

Clorpirifós, benzene hexachloride (lindane)

Highly toxic ((10 � 50)

Methyl-azinphos, fonofos

Extremely toxic (<10)

Carbofuran, terbufos

Source: Freemark & Boutin,1995 in Frighetto, 1997,p.427. MCPA = (4 �cloro-2-methylfenoxi) acetic acid ethyl; EPTC = ethyl dipropilithiocarbamate; 2,4-D = acid (2,4- diclorofenóxi). * Names in bold are because they are also used in BAP, according to the survey.

1

Annexe E

Survey of different types of agricultural chemical containers for the period 1987 to 1997

10

20.000.000

40.000.000

60.000.000

80.000.000

100.000.000

120.000.000

140.000.000

MetallicTotal plasticGlassWater-solublePlastic bagPaper bagCardboard cartidgeCardboard boxFibreglass can

Source: ANDEF, 2002. OBS.: Data for the water-soluble containers are only available from 1997 onwards, probably as a result of relatively new container on the market.

2

Annexe F

Principal active compounds with high surface water contamination potential in Primavera do Leste, MT in 1997

High potential for contaminatory surface water

Water-soluble

Associated with sediments in suspension

• Ethyl clorpirifos • lambda cialotrine • melthomil • Mancozeb • Triadimefon • Atrazine • Metribuzin • Simazine • Flumestsulan • Fomesafen • Glyphosate • Imazetapyr • Imazaquim • Metolachlor • Ethyl clorimuron

• Ethyl clorpirifos • Endosulfan • Lambda cialotrine • Mancozeb • Trifuralin • Glyphosate

Source: Dores and Freire (2001: p. 35)

3

Annexe G

Number of irrigated farms in the Upper Paraguay basin in MT -1995/1996

Municipalities in Pantanal Basin Number of farms Total of irrigated holdings in Mato Grosso state 1.047 Micro-region of Alto Pantanal 52 Barão de Melgaço 02 Cáceres 30 Poconé 20 Micro-region of Alto Paraguai 10 Alto Paraguai 01 Arenápolis 08 Nova Marilândia 01 Micro-region of Cuiabá 110 Chapada dos Guimarães 33 Cuiabá 09 Nossa Senhora do Livramento 14 Santo Antônio do Leverger 28 Várzea Grande 26 Micro-region of Rosário Oeste 22 Acorizal 12 Jangada 09 Rosário Oeste 10 Micro-region of Parecis 08 Diamantino 08 Micro-region of Alto Araguaia 07 Alto Araguaia 01 Alto Garças 05 Alto Taquari 01 Micro-region of Primavera do Leste 35 Campo Verde 35 Micro-region of Rondonópolis 120 Dom Aquino 09 Itiquira 04 Jaciara 37 Juscimeira 08 Pedra Preta 08 Rondonópolis 56 São José do Povo 02 São Pedro da Cipa 06 Micro-region of Tesouro 21 Guiratinga 06 Poxoréo 13 Tesouro 02 Micro-region of Jaurú 80 Araputanga 01 Figueirópolis do Oeste 02 Glória do Oeste 01

4

Municipalities in Pantanal Basin Number of farms Indiavaí 01 Jauru 04 Lambari do Oeste 11 Mirassol do Oeste 30 Porto Esperidião 01 Rio Branco 04 São José dos Quatro Marcos 25 Micro-region of Tangará da Serra 90 Barra do Bugres 07 Denise 10 Nova Olímpia 04 Porto Estrela 03 Tangará da Serra 66 Total number of irrigated farms in the basin 574 Source: Censo Agropecuário, FIBGE, 1995/1996.

5

ANEXO H

Quantidade de Estabelecimentos Agropecuários com Irrigação na Bacia do

Paraguai no Mato Grosso do Sul � 1995/96.

Municipalities in Pantanal Basin Number of farms Total of irrigated holdings in Mato Grosso state 1.430 Micro-region of Taquari 39 Camapuã * 09 Coxim 04 Pedro Gomes 04 Rio Verde de MS 08 São Gabriel do Oeste 13 Sonora 01 Micro-region of Campo Grande 329 Bandeirantes * 13 Campo Grande * 140 Corguinho 04 Jaraguari * 88 Rio Negro 10 Rochedo * 05 Sidrolândia * 26 Terenos 43 Micro-region of Cassilândia 07 Costa Rica * 07 Micro-region of Aquidauana 19 Anastácio 02 Aquidauana 05 Dois Irmãos do Buriti 04 Miranda 08 Micro-region of Baixo Pantanal 21 Corumbá 13 Ladário 06 Porto Murtinho 02 Micro-region of Bodoquena 43 Bela Vista 05 Bodoquena 03 Bonito 12 Guia Lopes da Laguna 09 Jardim 09 Nioaque 05 Micro-region of Dourados 07 Antônio João 07 Total number of irrigated farms in the basin 465 Source: Censo Agropecuário .FIBGE, 1995/96

6

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