Growth and yield of late sown rice varieties under various nitrogen management practices

Late sowing in rice cultivation reduces the effective growing window, adversely affecting crop performance and nitrogen use efficiency (NUE). Adopting short-duration varieties along with efficient nitrogen management practices can mitigate these effects. A field experiment was conducted during kharif 2021 at ICAR-Indian Institute of Rice Research, Hyderabad, to evaluate the performance of short-duration rice varieties under late-sown conditions and identify suitable nitrogen management strategies. The experiment was laid out in a split-plot design with three replications. The main plot treatments included three short-duration rice varieties: DRR Dhan-44, MTU 1010, and MTU 1156. The subplot treatments comprised four nitrogen management strategies: recommended dose of nitrogen (RDN) @ 120 kg N ha-1, slow-release silicon-coated urea (SRSCU) @ 90 kg N ha-1, Leaf Colour Chart (LCC)-based application @ 105 kg N ha-1, and Soil Test Crop Response (STCR)-based application @ 114.5 kg N ha-1. Among the varieties, MTU 1156 recorded the highest grain yield (5.71 t ha-1), dry matter accumulation (12.43 t ha-1), leaf area index (4.12), and productive tillers (285 m-²). Among nitrogen treatments, LCC-based application @ 105 kg N ha-1 resulted in the highest grain yield (5.76 t ha-1) and was statistically at par with RDN. SRSCU recorded the lowest yield. The highest partial factor productivity of N (PFPN), was observed in MTU 1156 (55 kg grain kg-1 N). The study concludes that MTU 1156 combined with LCC-based nitrogen management is an effective strategy for sustaining rice productivity under late-sown conditions.