Abstract

                                A field experiment was conducted at the Research Farm of Indian Institute of Technology, Kharagpur, India to evaluate the effects of nitrogen and irrigation levels under different sowing times on wheat during winter seasons (November-March) of 1978-79 and 1979-80. The grain yield was highest when sowing was done during the second fortnight of November. Delaying the sowing beyond 30th November resulted in decreased yields. Early sowing also produced significantly less yield as compared to normal sowing time. Grain yield Increased significantly upto 100 kg N/ha. Irrigations scheduled at 0.8 IW/CPE ratio recorded the highest grain yield. Nitrogen uptake was. maximum when sown at normal time. Water-use efficiency (WUE) decreased with increase in IW/CPE ratio from 0.8 to 1.0. Nonetheless, relatively more moisture was extracted from the upper layer at 1.0 IW/CPE ratio as compared to 0.6 and 0.8 ratios. However, soil moisture extraction from deeper layer was comparatively more under 0.6 IW/CPE than under 0.8 and 1.0. Application of nitrogen favoured the extraction of soil moisture from deeper layer.

Key words : Winter wheat, Sowing time, Nitrogen uptake, water use Efficiency, Grain yield.