Smita

Select Expert: 
Dr. Sheo Bardan Yadav
Question: 
Test Question--How to find out water requiremnt of different crops and reduce irrigation water requirement?
Answer: 
How to find out water requiremnt of different crops and reduce irrigation water requirement? Water requirement of crop is the quantity of water regardless of source, needed for normal crop growth and yield in a period of time at a place and may be supplied by precipitation or by irrigation or by both. WR = CU + application losses + water needed for special operations. Water requirement of crop is the quantity of water regardless of source, needed for normal crop growth and yield in a period of time at a place and may be supplied by precipitation or by irrigation or by both. Water is needed mainly to meet the demands of evaporation (E), transpiration (T) and metabolic needs of the plants, all together is known as consumptive use (CU). Since water used in the metabolic activities of plant is negligible, being only less than one percent of quantity of water passing through the plant, evaporation (E) and transpiration (T), i.e. ET is directly considered as equal to consumptive use (CU). In addition to ET, water requirement (WR) includes losses during the application of irrigation water to field (percolation, seepage, and run off) and water required for special operation such as land preparation, transplanting, leaching etc. Water requirement (WR) is therefore, demand and the supply would consist of contribution from irrigation, effective rainfall and soil profile contribution including that from shallow water tables (S) WR = IR + ER + S Reduce irrigation method through 1 Minimum tillage 2. Use anti transparent 3. Minimum weeds or no weeds. 4. Mulching - Straw mulch, black plastic film mulch, etc. 5. Use Micro irrigation, drip irrigation or sprinkler irrigation method 6. Use water stress resistant crop 7. Earthing up in wide space crops 8. Alternate furrow irrigation method