Fertilizer schedule under limited irrigation with zero-tilled wheat (Triticum aestivum) after rice (Oryza sativa) in north-west Himalayas

Abstract

Field experiment was conducted for two years during 2005-06 and 2006-07 at CSKHPKV, Rice and Wheat Re- search Centre, Malan to find out the fertilizer schedule for limited irrigation zero-tilled wheat {Triticum aestivum (L.) emend. Fiori & Paol.}. Five nitrogen levels viz., 0, 60, 90, 120 and 150 kg/ha along with 40 kg P O and 40 kg K O/ 2 5 2 ha in main plots and three time-methods of fertilizer application viz. M1: Placement of 1/3 N with full P and K as basal & topdressing 2/3 N at first node stage, M : Broadcast of 1/ N with full P and K as basal & topdressing 2/3 N at 2 3 first node stage, and M : Broadcast of full P and K as basal & full N one month after sowing, in sub-plots were 3 tested using split plot design replicated thrice. Significant response of wheat to nitrogen application was observed up to 150 kg N/ha, which was more profitable too. Grain and straw yield of the crop was significantly higher at 150 kg N/ha compared to lower levels. Increase was 30.6 (0.75 t/ha) and 27.0 (0.59 t/ha) per cent over the 90 kg N/ha in first and second year, respectively. Mean net returns were 33,950/ha and benefit : cost ratio 2.45 were the highest at 150 kg N/ha. N use efficiency was 11.0 & 13.2 kg grain/kg N applied at this level in 2005-06 and 2006- 07, respectively. The relationship between grain yield and N was quadratic in nature predicting still higher dose of optimum N. Wheat grain yield was significantly varied by time and method of fertilization application. In 2005-06 which was a drought like year at initial phase, application of full dose of N one month after sowing (M ) recorded 3 significantly higher grain yield (2.69 t/ha) compared to 1/ N applied at sowing time and 2/3 N at first node in M and 3 1 M treatments. Whereas in 2006-07 rainfall was comparatively well distributed and application of 1/3 N with full P 2 and K as basal placement (M ) recorded significantly higher values of grain yield and straw yield compared to M 1 2 and M treatments. Similarly M was more economical (net returns 30,307/ha, 2.32 B:C) in drought like year and 3 3 M in 2006-07. Thus, placement of 50 kg N, 40 kg P O and 40 kg K O/ha as basal dose followed by topdressing 1 2 5 2 of 100 kg N/ha at first node stage be adopted to realize more productivity of zero-tilled wheat under limited irriga- tion conditions in north western Himalayas. However, if there is dry spell during the initial crop phase, Broadcast of full P & K as basal and full N one month of sowing is also effective.