LAUSR

With the world population hitting 8 billion and the global climate becoming more erratic with pronounced droughts, floods, water shortages and storage depletions, the need for optimal soil and water conditions for high crop productivity and food security has become ever more urgent. There is a growing effort towards enhancing water storage in the root-zone soil layer (as a rainwater-harvesting strategy) to increase crop productivity. This study analysed the effects of biochar and deficit irrigation on rice productivity under greenhouse conditions. Grain yield, plant height, tiller number and biomass yield under 0% biochar (B1) were respectively 13.6, 6.4, 27.4 and 3.0% higher for moderate deficit irrigation (I2) than for flood irrigation (I1). Also in terms of tiller number, I2 performed better than I1 by 45.8 and 69.2% under B2 (4% biochar) and B4 (16% biochar), respectively. While for biochar the highest crop productivity was under B2, this changed vastly under the combined effects of irrigation and biochar. This suggested that crop productivity was as much dependent on irrigation as on biochar treatment. The variations in productivity could provide farmers with the choice of treatments or treatment combinations that are best suitable for their local agro-edaphic, hydroclimatic and socio-economic conditions. Copyright © 2017 John Wiley & Sons, Ltd.