|Author:||Zwart, S. J. ; Bastiaanssen, W. G. M.|
|Book Group Author:||NA|
The great challenge of the agricultural sector is to produce more food from less water, which can be achieved by increasing Crop Water Productivity (CWP). Based on a review of 84 literature sources with results of experiments not older than 25 years, it was found that the ranges of CWP of wheat, rice, cotton and maize exceed in all cases those reported by FAO earlier. Globally measured average CWP values per unit water depletion are 1.09, 1.09, 0.65, 0.23 and 1.80 kg m-3 for wheat, rice, cotton seed, cotton lint and maize, respectively. The range of CWP is very large (wheat, 0.6-1.7 kg m-3; rice, 0.6-1.6 kg m-3; cotton seed, 0.41-0.95 kg m-3; cotton lint, 0.14-0.33 kg m-3 and maize, 1.1-2.7 kg m-3) and, thus, offers tremendous opportunities for maintaining or increasing agricultural production with 20-40% less water resources. The variability of CWP can be ascribed to: (i) climate; (ii) irrigation water management and (iii) soil (nutrient) management, among others. The vapour pressure deficit is inversely related to CWP. Vapour pressure deficit decreases with latitude and, thus, favourable areas for water wise irrigated agriculture are located at the higher latitudes. The most outstanding conclusion is that CWP can be increased significantly if irrigation is reduced and crop water deficit is induced.
|Pages:||115 - 133|
|Journal:||Agricultural Water Management|
climate, cotton, crop yield, irrigation, latitude, maize,plant water relations, reviews, rice, vapour pressure, water deficit,water use efficiency, wheat, Gossypium, Oryza, Oryza sativa, Triticum,Triticum aestivum, Zea mays, Malvaceae, Malvales, dicotyledons,angiosperms, Spermatophyta, plants, eukaryotes, Poaceae, Cyperales,monocotyledons, Oryza, Triticum, Zea, corn, paddy, vapor pressure,watering, Field Crops (FF005) (New March 2000), Plant Water Relations(FF062), Plant Production (FF100), Soil Water Management (Irrigation andDrainage) (JJ800) (Revised June 2002) [formerly Soil Water Management],Meteorology and Climate (PP500)