Influence of nitrogen levels, irrigation regimes and planting methods on growth attributes and yield of spring maize

A field experiment was conducted during spring season of 2011 and 2012 in split-plot design keeping combinations of planting methods (bed and ridge) and irrigation regimes (Iw: CPE ratio of 0.9, 1.2 and 1.5) in main plots and nitrogen levels (0, 100, 125 and 150 kg N ha⁻¹) in sub plots with three replications on sandy loam soil which had average bulk density of 1.60 g cm⁻³. Grain yield, growth attributes viz. number of leaves per plant, leaf area index and dry matter accumulation and growth indices viz. crop growth rate, relative growth rate and net assimilation rate were found to be statistically similar in bed and ridge planted crop. however, irrigation scheduling at 1.2 and 1.5 IW: CPE resulted in similar grain yield, growth attributes and crop growth rate but significantly more than 0.9 Iw: CPE. Application of 150 kg N ha⁻¹ and 125 kg N ha⁻¹ recorded statistically similar grain yield, growth attributes and crop growth rate which was significantly higher than control. Chlorophyll content of leaves increased with increase in nitrogen level from 0 kg N ha⁻¹ to 150 kg N ha⁻¹. Leaf area index at 60 days after sowing (DAS) was maximum in the crop raised with irrigation scheduling at 1.5 Iw: CPE with 150 kg N ha⁻¹ which was statistically at par with 1.5 Iw: CPE with 125 kg N ha⁻¹ and 1.2 Iw: CPE with 150 kg N ha⁻¹.