Nutrient omission: Its effects on yield, water productivity and nutrient use efficiency of rabi sorghum under rainfed and irrigated conditions

A field experiment was conducted to study response of rabi sorghum to nutrient omission under rainfed and irrigated conditions during 2020 at All India Coordinated Research Project on Sorghum, Main Agricultural Research Station, University of Agricultural Sciences, Dharwad. The experiment was laid out in split plot design having two main plots and 9 sub plots using CSV - 29 R variety of sorghum. The results indicated that significantly higher yield (44.87 q ha-1), stover yield (8.52 t ha-1), water productivity (2.90) and higher agronomic use efficiency (29.73) and physiological use efficiency (33.63) of nitrogen of rabi grain sorghum were recorded under irrigated condition. Among nutrient omissions, application of 50:25 kg NP ha- 1 + FYM @ 3 t ha-1 + ZnSO4 @ 15 kg ha-1 recorded significantly grain yield (49.56 q ha-1), stover yield (9.55 t ha-1), water productivity (2.56) and higher agronomic use efficiency (34.58) and application of 50 kg N ha-1 + ZnSO4 @ 15 kg ha-1 + FYM @ 3 t ha-1 observed physiological use efficiency (38.18). Among interactions application of 50:25 kg NP ha-1 + FYM @ 3 t ha-1+ ZnSO4 @ 15 kg ha-1 recorded significantly grain yield (54.73 q ha-1), stover yield (10.80 t ha-1), water productivity (3.55) and higher agronomic use efficiency (38.66) and application of 50 kg N ha-1 + ZnSO4 @ 15 kg ha-1 + FYM @ 3 t ha-1 observed physiological use efficiency (40.01) under irrigated condition.