Effect of irrigation schedules of domestic waste water on growth and yield of fodder sorghum

An experiment was conducted to evaluate the effect of irrigation schedules of domestic wastewater on growth and yield of fodder sorghum (Sorghum bicolor L. Moench) during kharif season (May to September, 2013) in micro-plots at ICAR-Central Soil Salinity Research Institute, Karnal (Haryana). The experiment was laid out in factorial randomized block design consisting of nine treatment combinations of three irrigation water quality levels (tube well water, cyclic use of tube well water: sewage water, sewage water) and three irrigation schedules based on ID (irrigation depth)/CPE (cumulative pan evaporation) ratio levels (0.8, 1.0, 1.2) with four replications. Irrigation with sewage water and scheduling at 1.2 ID/CPE ratio resulted significant (P<0.05) increase in plant height, number of leaves per plant, leaf area index, leaf to stem (green and dry) biomass and green fodder yield. A significant (P<0.05) decrease was observed in dry matter content in sewage water as compared to tube well water and 0.8 ID/CPE ratio, respectively. The green fodder yield in sewage water was 14.4% and 25.0% higher as compared to tube well water at 1^st and 2^nd cut, respectively. The increment in green fodder yield observed at 1.2 ID/CPE ratio as compared to 0.8 was 15.3% at 1^st cut (P<0.001) and 20.7% at 2^nd cut (P<0.001). Continuous use of sewage water for irrigation tended to increase soil electrical conductivity (EC) and decreased soil pH. The findings indicated that sorghum can be profitably grown for quality fodder with use of sewage for irrigation scheduled at ID/CPE ratio up to 1.2.