Effect of Irrigation and Nitrogen on Yield, Water and Nitrogen Use Efficiency in Rajmash ( Phaseolus vulgaris L.)

A field experiment was conducted during winter season of 1996-97 and 1997-98 to study the effect of irrigation (IW/CPE ratio of 1.0, 1.2 and 1.4) and nitrogen (0, 40, 80 and 120 kg/ha) on yield, water and nitrogen use efficiency in rajmash. Scheduling irrigation at IW/CPE of 1.4 had significant effect on yield (1854 kg/ha). It responded to application of nitrogen @ 80 kg/ha (1912 kg/ha). Rajmash extracted 35.3 cm of water having consumptive use (CU) of 40.5 cm and WUE of 45.8 kg/ ha-cm at IW/CPE ratio of 1.4. Application of nitrogen @ 80 kg/ha resulted in the extraction of 34.0 cm of water having CU 39.3 cm and WUE of 48.7 kg/ha-cm. Irrigation made at IW/CPE ratio of 1.4 had the highest apparent nitrogen recovery (44.92%) and agronomic nitrogen use efficiency (9.37 kg seed/kg N applied). The physiological efficiency (PE) ranged from 20.56 to 21.85 kg seed/kg N uptake at varying irrigation levels. Nitrogen applied at 40 kg/ha had the highest ANR%, PE and ANUE, which decreased progressively with successive increase in nitrogen levels.