Resumen de Optimizing soil moisture regime to increase water use efficiency of sugarcane (Saccharum spp. hybrid complex) in subtropical India
P. N. Singh, S.K. Shukla, V.K. Bhatnagar
Field studies were conducted for 2 years in alluvial soils of north India to determine water use, water use efficiency and yield of sugarcane on a sandy loam and a silty clay loam soil under various moisture regimes. Irrigation scheduling was based on the ratio between irrigation water and cumulative pan evaporation (IW/CPE). Deep irrigations at 80 mm were applied at IW/CPE ratios of 0.25, 0.50, 0.75, 1.00 and 1.25. Total water use was higher in the plant crop than the ratoon crop under all IW/CPE ratios. Mean water use efficiency (WUE) of plant cane (71 kg/ha/mm) was also higher compared to ratoon cane (63 kg/ha/mm). On the heavier silty clay loam soil, losses through deep percolation ranged from 25 to 30% in the first crop and 7�13% in the second crop season. Maximum effective rainfall was recorded in the driest soil moisture regime. Mean cane yield on the sandy loam soil increased significantly up to 1.0 IW/CPE ratio. We conclude that in subtropical India, irrigation of sugarcane during the tillering period should be applied at 0.75 and 1.00 IW/CPE ratios in silty clay loam and sandy loam soils, respectively
