Impacts of Effects of Deficit Irrigation Strategy on Water Use Efficiency and Yield in Cotton under Different Irrigation Systems

Irrigated cotton (Gossypium hirsutum L.) growers in the Murray-Darling Basin (MDB) of Australia, are challenged by limited water availability. This modelling-study aimed to determine if deficit irrigation (DI) practices can potentially improve use efficiency (WUE) for furrow (FI), overhead sprinkler (OSI) and subsurface drip (SDI) systems. We validated Agricultural Production System sIMulator (APSIM) against observed lint yield crop biomass accumulation different management practices. The model achieved concordance correlation coefficients 0.93 0.82 yields, respectively. was then applied evaluate impacts levels DI on yield, WUE across growing locations MDB (Goondiwindi, Moree, Narrabri, Warren), during period from 1977 2017. FI system were no irrigation, full (TF) irrigated one out four, three, two, two three four TF events. For OSI SDI systems, TF, 20% 40% 60% 80% TF. Lint maximised under systems most applying However; modelling identified that at These results suggest there significant gains agronomic performance be gained through application with these FI, had benefit terms increasing while showed marginal some situations. result is due greater exposure periodic stress occurred when an system. northern MDB, savings could realised production both adopted a extent, depending location