Yield, water, radiation and nitrogen use efficiencies of wheat (Triticum aestivum) as influenced by nitrogen levels in a semi-arid environment

Abstract

A field experiment was conducted during the winter (rabi) season of 2009–10 and 2010–11 on a sandy-loam soil in New Delhi, to study the effect of nitrogen levels on the water, radiation and nitrogen-use efficiencies of wheat [Triticum aestivum (L.) emend. Fiori. & Paol.] cultivars. The treatments comprising 2 wheat cultivars (‘PBW 502’ and ‘DBW 17’) and 3 nitrogen levels (N0: 0kg N/ha, N60: 60 kg N/ha and N120: 120 kg N/ha) were laid out in factorial randomized block design (RBD). Both cultivars were statistically at par for grain yield, above-ground biomass yield, water-use efficiency (WUE) and radiation-use efficiency (RUE). Treatments N120 registered 71% and 25% higher grain yield than N0 and N60 treatments respectively. Water-use efficiency (WUE) of N120 (9.92 kg/ha/mm) was significantly highest, followed by N60 (8.40 kg/ha/mm) and N0 (6.56 kg/ha/mm) treatments. Similarly, radiation-use efficiency (RUE) of N120 (2.49 gm/MJ) was significantly higher than N60 (1.90 gm/MJ) and N0 (1.85 gm/MJ) treatments. The partial factor productivity of nitrogen (PFPN) of the cultivar ‘PBW 502’ (48.96 kg grain/kg nitrogen applied) was significantly higher than that of ‘DBW 17’ (42.23 kg grain/kg nitrogen applied). Nitrogen @ 60 kg/ha (N60) showed significantly higher PFPN (56.08 kg grain/kg nitrogen applied) than N120 (35.10 kg grain/kg nitrogen applied) treatment. Therefore, cultivar ‘PBW 502’ or cultivar ‘DBW 17’ can be grown with 120 kg N/ha for obtaining higher grain yield, above ground biomass, WUE and RUE in the semi-arid tropical environment of Delhi region.