Sugarcane response to different soil water replenishment‐based deficit irrigation treatments during different growth stages in an Indian semi‐arid region*

Abstract

AbstractThe objective of this study was to investigate the effect of a specified water deficit during a specified growth stage by replenishing root zone soil water. A field experiment was conducted with 27 treatments in randomized block design comprising groupings of different root zone soil water replenishment levels (100%, 70%, and 40%) during different growth stages (tillering, grand growth, and maturity) over three full‐year seasons of 2015–2017 in clay soils of semi‐arid western India. The full‐season 100% soil water replenishment produced higher yield (174 t ha−1), net monetary returns, and benefit‐cost (B:C) ratio that decreased linearly with linear decrease in water use. Full‐season 40% soil water replenishment caused a reduction in yield of about 40.7%, whereas a 70% replenishment caused a reduction in yield by 14%. The quality parameters of sugarcane improved non‐significantly in high‐water‐deficit conditions compared with full irrigation. The smaller range of water productivity in all seasons indicated a linear decrease when irrigation water increased and yields decreased under the different treatments. The net income and B:C ratio related to marketable cane yield was highest in 100% soil water replenishment (INR 274,000 ha−1 and 1.58, respectively) and then declined with the decrease in water use depth. The water deficit imposed during the long‐duration grand growth stage had adverse effects on cane yield, followed by tillering and maturity stages. Deficit irrigation scheduling at 100%, 70%, and 40% soil water replenishment at tillering, grand growth, and maturity stages, respectively, was appropriate. The water requirement of seasonal sugarcane under full irrigation and water deficit conditions was 1,320 and 1,150 mm, respectively.