Theme-IV-3-Technology options to enhance crop water productivity - An overview.

Abstract

In view of current water scarcity due to over-mining of groundwater in Punjab, it is imperative to enhance crop water productivity (economic yield per unit of water consumed as evapo-transpiration, ET). It calls for adopting measures that reduce percolation and soil water evaporation components of root-zone water balance. A critical appraisal of technology options show that most of the resource conserving technologies like land levelling, bed planting, zero-tillage and improved irrigation method and timing cause irrigation (apparent water) and energy saving, but they have little effect on ET. A part of irrigation saving is translated to ET (real water) saving through diversification to short-duration crops and varieties, shift of planting time to periods of low evaporative demand and straw mulching during hot periods of crop growth. It is the ET saving component that affects groundwater levels.