Productivity, profitability and nitrogen-use efficiency of barley (Hordeum vulgare) as influenced by weed management and nitrogen fertilization under hot semi-arid ecologies of Rajasthan

A field experiment was conducted during winter (rabi) 2012–13 and 2013–14 at research farm, Jobner, Rajasthan, to evaluate the effect of weed-management practices and nitrogen fertilization on productivity, profitability and N-use efficiency of barley (Hordeum vulgare L.). The results indicate that plots under twice hand-weeding (HW) 25 and 50 days after sowing (DAS) had the highest growth and yield attributes followed by metsulfuron methyl 4.0 g/ha applied at 30–35 days after sowing (DAS). Among weed-management practices, the highest grain and straw yields (5.21 t/ha; 7.13 t/ha) were obtained with 2 HWs and metsulfuron methyl (4.76 t/ha; 6.40 t/ha) treatments (pooled data 2 years). The highest net returns were also obtained with 2 HWs, and the increment to the tune of 7.0, 12.2 and 15.5% over metsulfuron methyl, 1 HW and 2, 4-D ester (0.5 kg/ha) respectively. Nitrogen 90 kg/ha significantly improved the yield attributes and yields over the control and 30 kg N/ha; however, it remained statistically at par with 60 kg N/ha. Metsulfuron methyl along with 90 kg N/ha was found to be best for benefit: cost ratio (4.37), followed by 2, 4-D ester (E) (4.09) over the HWs treatments. Two HWs proved the best for agronomic efficiency (AE) and apparent recovery (RE) of applied N (16.2 kg grain/kg N; 69.1%). Physiological-use efficiency (PE) of applied N was the highest in plots under carfentrazone-ethyl 15 g/ha at 30–35 DAS and 30 kg N/ha.