By :- A. R. SofiSoil Conservation Officer Agriculture Department Kashmir (J&K)

The thin layer on the surface of the Earth on which the living beings of the earth survive since it is the layer of materials in which plants have their roots, with large amount of nutrients.

Soil erosion: An agricultural production challenge

Soil erosion is a gradual process that occurs when the impact of water or wind detaches and removes soil particles, causing the soil to deteriorate. Soil deterioration and low water quality due to erosion and surface runoff have become severe problems worldwide.

The problem may become so severe that the land can no longer be cultivated and must be abandoned. Many agricultural civilizations have declined due to land and natural resource mismanagement, and the history of such civilizations is a good reminder to protect our natural resources.

Soil erosion by water occurs when bare-sloped soil surface is exposed to rainfall, the rainfall intensity exceeds the rate of soil intake, or infiltration rate, leading to soil-surface runoff.

Soil erosion can occur in two stages: 1) detachment of soil particles by raindrop impact, splash, or flowing water; and 2) transport of detached particles by splash or flowing water. Therefore, soil erosion is a physical process requiring energy, and its control requires certain measures to dissipate this energy.

Types of Erosiony

Sheet erosion (water) is almost invisible. Lighter coloured soils are a sign that over the years erosion has taken its toll.

Rill erosion:

occurs during heavy rains, when small rills form over an entire hillside, making farming difficult.Rill erosion

Gully erosion makes gullies, some of them huge, impossible to cross with farm machinery. Ephemeral erosion occurs in natural depressions. It differs from gully erosion in that the area can be crossed by farm equipment.

SOIL CONSERVATION Soil Conservation is the process by which the loss of soil is checked, reducing the velocity of run-off through erosion control measures for maximum sustained crop production and for protection of human lift. So conservation of soil is essential for sustenance of human life on the earth.

DEFINITION Soil conservation is set of management strategies for prevention of soil being eroded from the earth s surface or becoming chemically altered by overuse, salinisation, acidification, or other chemical soil contamination.

OBJECTIVE OF SOIL AND WATER CONSERVATION Enhancing and sustaining productivity of available

land stock for primary production systems of crop cultivation, livestock rising and forest management. Generating additional employment opportunities and income through secured livelihood in rural areas. Maintaining beneficial relationship between land and water cycles

OBJECTI E OF OI

ND TER CONSER ATION .. Contd.

Retarding Watershed degradation caused by deforestation, soil erosion, sedimentation, land degradation and hydrologic deterioration of the watersheds. Locating, reclaiming and developing Culturable wastelands, fallows other than current fallows and degraded lands to meet increasing and competing demands for additional land stock for various sectors

IMPORTANCE OF SOI CONSER ATION Most people know that they need clean air and clean water to stay healthy. Fewer people realize that their well-being also depends on the health of the soil. Soil supports the growth of most of our food and fibre, But soil also has a much broader, global role. Soil acts as a filter, cleaning air and water.

It exchanges gases with the atmosphere and thus influences the global climate. Soil receives organic wastes and recycles their nutrients back to plants; It (Soil) also holds and breaks down some toxic wastes, we must conserve it and use it in a sustainable manner.

DIFFERENT MEASURES FOR SOI CONSER ATION Mechanical Soil Conservation measures Mechanical measures include various engineering techniques and structure. This practices aim at some objective as follows: To divide a long slope of land into a series of shorter ones in order to reduce the velocity of run off water. To retain the water in the land for long period so as to allow maximum water to be absorbed and held in the soil and less water flows down the slope of the land at non-erosive velocity. To protect the soil against erosion by water.

Technological options for erosion management on newly cleared land

On steep slopes agronomic practices have got to be supplemented by mechanical measures for effective control of erosion, such as: a) Contour bunding, b) Graded bunding, c) Bench Terracing, d) Bunding and Levelling e) Land modification (Zingg conservation bench Terraces)

For Non Agri. Lands: Staggered Contour trenches Live Check dams, Silvi Pastoral System, Live Fencing, Controlled Grazing, etc;

Runoff and Soil Loss under Intercropping:Treatment ___________ 1) Maize alone 2) Maize & Pulses (Moong) Runoff (% of Rainfall) 38.4% 13.1% Soil Loss (Tones / ha.) 17.5 5.3

Source: CSWCRTI - Dehradun

TERRACES FOR DIFFERENT OBJECTIVES

Objective

Type of terrace 1.Level terraces for irrigation 2. Bench terraces built in a single operation 3.Progressive reduction of slope

Soil Management

Objective

Type of terrace

ater Management

4.Absorb all rain, 5. Absorb some rain with emergency overflow (contour bund) 6.Controlled run-off (graded bund / channel terrace), 7.Controlled reduced run-off -ridging, -tied ridging,

Objective Crop Management

Type of terrace 8.Intermittent terraces, -orchard terrace, -platforms -hillside ditches,

Criteria for Land Levelling: Land Levelling is influenced by following factors:Soil : Its type, texture, structure and depth, etc; mClimate: It takes into account the rainfall, evaporation, temperature and wind velocity, etc; m Crops to be grown: These effect the irrigation methods and give an idea about the extent of levelling required,

mMethods of Irrigation: As per availability, mDesire of farmers:It is essential to know the desire of farmers while selecting the design standards based upon the amount to be invested in levelling.

Steps involved in Levelling:Division of entire field in smaller units, Planning and surveying, Methods of levelling, Earth work calculations, Execution of levelling operation in the field, and Equipments and maintenance of work.

The important mechanical soil conservation measures are as follows: Contour bunding Contour

bunding consists of building earthen embankment at intervals across the slope and along the contour line of the field.

A series of such bund divide the area into strips and act as barrier to the flow of water.(Runoff)

Contour bunding .. Contd.

As a result, the amount and velocity of

run-off are reduced, resulting reducing the soil erosion. Contour bunding is made on land where the slope is not very steep and the soil is fairly permeable. Contour bunding works are carried out over wide areas of state.

Terr

i

A terrace is an embankment of ridge of earth constructed across the slope to control runoff and to minimize soil erosion. A terrace reduces the length of the hill side slope, thereby reducing sheet and rill erosion and prevents formation of gullies.Land levelling for :1)Erosion Control, 2) Moisture Conservation, 3) Irrigation and 4) Drainage.

Different types of Terraces:

Broad based ridge terrace: It consists of making wide but low bunds on the contour lines by excavating soils from both sides of terrace. This is practiced in areas where the rainfall is relatively low. Contour trenching: It consist of making a series of deep pit (i.e. 2ft. wide and 1ft. deep) or trenches across the slope at convenient distance. The soil excavated from the trenches is deposited on the lower edge of the trenches where forest trees are planted

Channel terrace: It consists of making of wide but shallow channels across the slope of the land either exactly on contour line or with a slight grade (0.1 to 0.2 per cent). In this process, the excavated soil is placed along the lower edge of the channel in the form of low ridge. Also called Graded bund. Bench terracing: It consists of transforming relatively steeps land into a series of level or nearly level strips or steeps running across the slope. The soil materials that are excavated from the upper part of the terrace is used in filling the lower part and a small bund is also raised along the outer edge of the terrace to check the downward flow of rainwater and also soil erosion. Narrow based terrace: It consists of making a number of narrow based ridges or bunds at a distance of 1m to 2m across the slope of the land at suitable intervals in high rainfall areas.

Table Top Bench Terracing for Paddy cultivation in hilly areas of Kashmir - BANDIPORE

Ploughed Terraced agri. Land for paddy cultivation IN KASHMIR nDISTRICT BANDIPORE

Gully Plugging For Silt Control & Rain water harvesting / Ground water Recharge:

Rains have scoured away constantly at earths surface and transported from place to place and as such streams channels and gullies have been carved out. On an average more than 70% rainfall is lost as runoff (not utilized) carrying with top fertile soil i.e; depletion of soil (erosion) and deposition in low laying areas incl. lakes, rivers reservoirs, etc;

Due to the non adoption of Soil & Water conservation measures, the gullies have been formed due to the traditional farming practices practised by the farmers. Therefore, ta ing into consideration the magnitude of the problem the department of Agriculture has come up with so many number of project reports more scientifically on micro watershed basis duly approved by D.L.I.C in all the districts.

Aims and Objectives: The following are the main aims and objectives: To reduce the velocity of runoff water by constructing some engineering structures, i.e; check dams and protection walls at different elevations of the Gully & nallah thereby protecting the agri. Lands and to capture large soil particles. To prolong the life of trees on either side of the nallah. To enhance the chances for establishment of natural vegetation / soil binders. To protect the lands which are otherwise sedimented by small boulders and pebbles and pose grave problem during the cultivation.

To i ter e t r off a oderate eak e. flo a d ol To i rea e lar e a or tion of availa le ater leading to all round rain i rove ent of oi ture onditions. To enhance ground ater recharge and to i rove dry weather flow. To provide irrigation potential to mini commands. To intercept and reduce silt and thus reduce sediment production into the streams and finally into the reservoirs. To increase total production as well as total resource for the entire area.

1. Rain water harvesting / Ground water Recharge: The measures under this activity will help in collecting and using rain water and in recharge of ground water on watershed basis, viz; W. H. Tanks, Dugout out ponds and ground water recharge pits with staggered contour trenches. These structures will help in greater absorption of water on large areas and also hold some in between dry spells. 2. Roof Water Harvesting: The rain water from roof of houses on hill slopes accelerates the runoff, thereby causing further soil erosion problems. It is suggested to harvest the roof water at selected houses / points by constructing low water harvest ponds. The water thus harvested can be utilized for various purposes within the village when there will be scarcity or can infiltrate into the soil and thus recharge the ground water.

3. Contour t r r nc ing: Excavate tre c es al g a if r t et rti f catc e ts. is activity ist re c iti s a t s accelerate tre c es ill als rea t e vel city f t r g t e s il sl ly a travels . nefits: t e etter ty e f la i t e catc e ts. e c t r tre c es are ( e e i g t e sl e f t e la ).

level acr ss f t e sl e f la i ill el t create re fav ra le t e gr t f t e trees. ese r ff. e rai ater erc lates i le a excavate l er secti s f t e at s ita le i tervals

4. Gully Control Structures:

Structures to prevent encroachment of gully heads upward. Gully erosion is an advanced stage of rill erosion, while the later is an advanced stage of sheet erosion. Stabilization of gullies through vegetation is a difficult task when the gullies have to be used for conveying runoff. In such cases mechanical measures have to be adopted to prevent washing away the top fertile soil and sediment flow down.

The mechanical structures such as RR dry stone masonry, earthen dams using empty cement bags filled with earth shall have be provided to convey the runoff over the critical portions of the gully.

Initial Stage of sheet and rill erosion

View of gully erosion

Construction of Check dams: In control of gullies, the erosive velocities will be reduced by flattering out the steep, uniform gradient of the gully, by constructing a series of check dams which transform the longitudinal gradient into a series of steps with low risers and long flat treads. This collects sufficient soil and water to enable proper growth of vegetation and to check channel erosion and recharge ground water. To make the water to walk instead of run. Three types of check dams are normally practicing depending upon the soil profile; (i) Gabion structure check dams, (ii) RR dry stone masonry check dams and (iii) Earthen checks (using empty cement bags filled with earth.)

Gully plugging through stone filled check dams

(i) Gully plugging works 1. Construction of rock fill dams The rock fill dams are constructed with locally available stones and boulders along the gullies or small streams from ridge to valley in all the catchments. These are designed to retard the flow of water. These will also retain some quantity of sediments and moisture, which helps in establishing vegetation.

Rock fill dams

(a) RR dry stone masonry check dams: These check dams are made from boulders / stones in the steep gullies and drainage lines in such a way that the top of one is leveled with the bottom of upper successive check dam, so as to diminish velocity of runoff and force sediment deposition.

Left : Series of Check dams in upper reaches, Right: View of Check dams just above The Agri. Lands (Thereby protecting the agri. Lands from silt, etc;)

(b) Earthen dams: These check dams are made from empty cement bags filled with earth and placed in dry in the bed of gully one over another in alternate manner along with ramming and dressing. The soil should be excavated at least 500 mts. away through staggered trenches and should match with the soil profile of the gully so that the earth get deposited to stop the gully format.

Gully plugging using Empty cement bags filled with Earth Arable Lands (Agri. Lans)

Gully Plugging with Vegetative Support in Upper Reaches using Empty Cement bags filled with Earth

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