Does straw mulch alter soil evaporation, yield, and quality of sugarcane?

Abstract

Cumulative soil evaporation estimation without CE(s − i) and with CE(s + i) inundation days viz. rainfall or irrigation days is an important aspect, affecting yield and quality of sugarcane, lacking in the literature. To this end, present replicated study conducted during spring 2019–2020 in irrigated sugarcane under semi-arid conditions, with differential rice straw mulch rates viz. 0, 4, 6, and 8 t ha−1 constituting T1, T2, T3, and T4 treatments, respectively. Attempts being made to delineate CE(s − i), CE(s + i) for which mini-lysimeters and pan evaporation (Ep) data used, respectively, and their effect on yield and quality parameters of sugarcane. From tillering to grand growth stage, CE(s − i) from T1 reduced to 2.4, 9.7, and 26.5% in T2, T3, and T4 plots, respectively whereas 7.14 and 15.3% reductions recorded while shifting from T2 to T3 and T3 to T4 plots. However, CE(s + i) reduced to 1.4, 14.4, and 5.6% while shifting from T1 to T2, T2 to T3, and T3 to T4 plots. Periodic growth parameters viz. cane height, width, Brix, and relative leaf water contents reported to improve but non-significantly in T2, T3, and T4 plots as compared to T1 plots. Averaged SPAD readings were reported to 7.6, 14.9, and 17% higher at 311 DAS in T2, T3 and T4 plots, compared to T1 plots. T3 plots reported significantly higher cane yields and commercial cane sugar (t ha−1) than T1 and T2 plots but at par with T4 plots. Therefore, T3 plots loaded with 6 t ha−1 of mulch reported to reduce CE(s − i), CE(s + i), and improve cane yield, and quality.