2. Irrigation water
The suitability of irrigation water is determined by the following
criteria (shainberg and oster 1978)
1. TDS
2. Sodicity
3. Anion and cation components
4. Content of minor elements of particular importance of the crop
involved.
• Cations – calcium,magnesium,sodium and potassium
• Anions – carbonate,bicarbonate,sulphate,chlorine and Nitrate
• Minor elements – molybdenum,selenium,fluorine and Boron.
3. Adverse effect of poor quality water
• High sodium content in water causes deflocculation and low infiltration,
permeability.
• It causes surface impermeable layer and water logging reduce oxygen supply to
root zone
• High concentration of calcium restricts potassium uptake
• High magnesium induces calcium deficiency
• Soil salinity affects cell division, cell elongation and protein Synthesis
• Excessive soluble salt concentration restricts plant water uptake
• Bacteria are sensitive to high salt concentration
• Soils with high ESP becomes hard on drying and reduces workability
4. Management of saline water
Improved agronomic practice
1. Monsoon induced leaching is of immense value for maintaining salt balance
2. Construction of ON –FARM Reservoir
3. Selection of salt tolerant crops, varieties
4. Pre-sowing irrigation
5. Extra seed rate (20 – 30 %)
6. Method of sowing – Sowing on the bottom furrow on either side of ridges.
7. Seedling practice – Pearl millet and Ragi
8. Soil fertility management -25 % Extra nitrogen
9. Use of amendments-Organic manures & Green manuring
10. Provision of lateral and main drainage channels of 60 cm deep and 45 cm wide
11. Providing sub-surface drainage for lowering water table
5. Other management practices
• Over aged seedlings in rice
• Mulching
• Crop rotation
Salinity control with sloping beds
6. Irrigation management
1. More frequent irrigation
2. Alternate furrow irrigation
3. Drip irrigation
4. Sprinkler irrigation
5. Conjunctive use of fresh and saline water
6. Irrigation of good quality water at critical stages
7. Desalinization and rain water management –Israel,Kuwait,Greece
and USA
7. Management of alkali water
• Growing tolerant crops –Sugarbeet,datepalm,cotton
• Use of small quantities of water
• Growing low water requiring crops
• Application of organic manures after gypsum application
• Use of Gypsum bed/chamber
• Application of amendments-Gypsum
• Deep ploughing/Sub-soiling
• Providing surface and subsurface drainage
8. Waste water
• Besides the salinity and alkalinity hazard of water, some industrial
effluents and sewage water are also problem water that can be reused by
proper treatment.
• Waste water supplies not only nutrient but also some toxic elements such
as total solids of chloride, carbonate,bicarbonate,sulphate,sodium
chromium, calcium magnesium, etc., in high concentration.
• The effluent or waste water creates BOD (Bio chemical Oxygen Demand)
when directly used it causes suffocation on plants.
9. Management of waste water
• Dilute with good quality water in the ratio of 50:50 or 75:25
• Alternate irrigation with waste water and good quality water
Treatment of these waste water can be done by
1. Fill and draw tanks
2. Settling tank
3. Sludge removal tank
4. Aerobic and anaerobic treatment tanks etc.,
10.
11. References
• Minhas P.s and N.K. Tyagi Guidelines for Irrigation with Saline and
Alkali Waters. Bull. No, 1/98.CSSRI. Karnal-132001, India,pg. :36.
• Das D.K Introductory to soil science. 3rd edition.2014.Pg no.267-272
• Reddy S.R Irrigation Agronomy.2014.Kalyani publishers.Pg no.307-
331
• Yellamanda Reddy.T and G.H Sankara Reddy principles of agronomy.
5th edition 2016.Kalyani publishers Pg no. 382-383
