Micro irrigation for enhancing water productivity in field crops
Mark Richards. Irrigation The artificial application of water to the land or soil. Used to: assist...
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Transcript of Mark Richards. Irrigation The artificial application of water to the land or soil. Used to: assist...
Treated Effluent Re-Use for Agriculture
Mark Richards
IrrigationThe artificial application of water to the land
or soil.Used to:
assist in the growing of agricultural crops, protecting plants against frost, suppressing weed growth in grain fields preventing soil consolidation.
maintenance of landscapes,Re-vegetation of disturbed soils in dry areas
SHOULD ALWAYS BE ASSESSED TOGETHER WITH DRAINAGE
Irrigation & Agriculture
Irrigated agriculture has driven much of the increase in global food production over recent decades.
While only 20% of the world's farmland is irrigated, it produces 40% of our food supply.
Highest yields obtained from irrigation are more than double the highest yields from rainfed agriculture (FAO report).
Benefits of IrrigationImproving crop quality - most noticeable for
vegetable crops.Effective management of crop water needs –
supply water as needed.Planned agricultureImproved economics of farming
Significantly increasing crop yields particularly on sandy soils which have low moisture-holding capacities.
Increasing opportunities for double cropping.
Providing a means of liquid fertilizer application.Possible reduction in fertiliser use
Reduction in production cost
Irrigation NeedsIrrigated agriculture is dependent on an
adequate water supply of usable qualityQuality not normally paramount in Jamaica
Availability of adequate good supplyNo real need to meet standards
Impact of development on ground water and surface water causing concern
Need for global tradeReduced availability of water
Competition for water
WATER QUALITY-RELATED PROBLEMS IN IRRIGATED AGRICULTURE
SALINITY Salts in soil or water reduce water availability to the crop to such an
extent that yield is affected.WATER INFILTRATION RATE
Relatively high sodium or low calcium content of soil or water reduces the rate at which irrigation water enters soil to such an extent that sufficient water cannot be infiltrated to supply the crop adequately from one irrigation to the next.
SPECIFIC ION TOXICITY Certain ions (sodium, chloride, or boron) from soil or water accumulate
in a sensitive crop to concentrations high enough to cause crop damage and reduce yields.
MISCELLANEOUS Excessive nutrients reduce yield or quality; unsightly deposits on fruit or
foliage reduce marketability; excessive corrosion of equipment increases maintenance and repairs.
MICROBIAL CONTAMINATION air, soils and plants in the vicinity of the irrigation site
Concerns for Effluent Re-useIn quantitative terms, the volume of
wastewater available for re-use by irrigated agriculture is negligible when compared with the overall volume of water used for irrigation.
The potential impacts associated with water quality and agricultural re-use of wastewater are importanteconomically, environmentally and socially,
Sound planning needs far exceeds the relatively small quantities and areas involved
Global GAP Certification
Recommendationsmicrobial and biochemical properties will have
to be evaluated.values should then be compared with the
public health standards, consideration of the crop, soil and irrigation
system and consumption of the produceonly when the effluent meets these standards
should it be evaluated in terms of chemical criteria such as dissolved salts, relative sodium content and specific toxic ions
Irrigation InfrastructureIrrigation Schemes
Pump Stations
Wells Canals Pipes (km)
Rio Cobre 18 22 26 31.01St. Dorothy 8 7 28 -
Yallahs 3 3 - 15.21Mid-
Clarendon32 32 153 36.10
New Forest 2 4 - 26Hounslow 5 5 - 41.40Beacon/
Little Park3 3 - 27.83
Seven Rivers
- 1 - 2.96
Colbeck 1 1 - 8.60Braco 1 1 - 8.60Grand Total
73 79 207 194.24
Water Quality from Existing Sources
What Happens Elsewhere California Israel South Africa FR GermanyOrchards and vineyards
Primary effluent; no spray irrigation
Secondary effluent
Tertiary effluent, chlorination, No spray irrigation
No spray irrigation in the vicinity
Fodder fibre crops and seed crops
Primary effluent; spray irrigation
Secondary effluent, use on edible vegetables not permitted
Tertiary effluent
Pretreatment with screening and settling tanks.
Crops for human consumption that will be processed to kill pathogens
For spray no more than 23 coliform organisms per 100 ml.
Vegetables for human consumption 1000 coliform organisms per 100 ml in 80% of samples)
Tertiary effluent
Irrigation up to 4 weeks before harvesting only
Crops for human consumption in a raw state
For surface irrigation, no more than 2.2 coliform organisms per 100 ml.
Not to be irrigated with renovated wastewater unless they consist of fruits that are peeled before eating
Potatoes and cereals - irrigation through flowering stage only
Example from Israel
Further RecommendationCulture change initiative
Farmers are presently averse to the re-usePublic Consultations/Public Education CampaignDevelop capacity of treatment facility to maintain
constant effluent qualityLong-term monitoring data to substantiate
Contingencies for emergency managementDevelop nutrient management capacity to
manage soil impact of treated effluent.Full re-use of waste is recommended
Waste to energyFertilizer development
100% of Influent Reused