Water productivity, yield and agronomic attributes of maize crop in response to varied irrigation levels and biochar--compost application.

BACKGROUND: Due to the rapid increase in world population, the demand for freshwater is increasing day by day. There is also immense pressure on the agriculture sector to produce more food with limited supplies of water. About 75% of freshwater is used in crop production out of which 63% is lost due to poor farm practices and evapotranspiration. Enhancement of crop water productivity for sustainable agriculture production especially in areas having water scarcity plausibly contributes towards the solution of water scarcity. RESULTS: The combined application of biochar and compost has a highly significant impact on maize yield with increased grain production, i.e. 6.44 and 6.52 t ha^-1 at 60% irrigation level with combined application of biochar and compost as compared with control at 6.39 and 6.44 t ha^-1 at 100% irrigation level in autumn and spring seasons, respectively, by saving 40% of water. Furthermore, the highest value of water productivity (1.51 and 1.16 kg m^-3) was achieved at 60% irrigation level with combined application of soil amendments. Also, cost--benefit analysis has shown highest values of net benefit with soil organic amendments. CONCLUSIONS: It is concluded that addition of biochar and compost to soil has the potential to increase crop yield and growth even at low irrigation levels by enhancing water use efficiency. [ABSTRACT FROM AUTHOR]