Enhancing productivity of grain sorghum in Rabi season under varied nitrogen levels in South Odisha

In the current era of climate change, growing ecologically sound and climate-resilient crops can be considered a suitable adaptation option. In this regard, grain sorghum (Sorghum bicolour L. Moench) is distinguished for drought tolerance and adaptability to marginal lands, and plays a pivotal role in ensuring food and nutritional security in semi-arid and tropical regions as an alternative cereal, after rice and maize. However, suboptimal nitrogen (N) management limits its productivity. Considering the need to optimise nitrogen requirement, a field experiment was conducted during the Rabi season of 2024-25 at the M.S. Swaminathan School of Agriculture, Gajapati district, Odisha. The experiment was laid out in a Completely Randomised Block Design with 11 nitrogen levels ranging from 0 to 200 kg N/ha and replicated thrice. Phosphorus and potassium were applied uniformly, as recommended (40:40 kg/ha of P2O5 and K2O, respectively). The results revealed that increasing nitrogen levels significantly enhanced growth, yield attributes, and yield of sorghum. The highest plant height (277 cm), dry matter accumulation (1658.13 g/m²), leaf area index (4.72), and stem girth (7.4 cm) were recorded with 200 kg N/ha. Similarly, panicle length (38.4 cm), panicle weight (172 g), number of grains per panicle (1384 grains), and test weight (29.6 g) were noted under the same treatment. The application of 200 kg N/ha produced the highest grain (3642 kg/ha), stover (12146 kg/ha), and biological yield (15788 kg/ha), remaining statistically similar to 160 and 180 kg N/ha in most cases. Although the highest yield was obtained with 200 kg N/ha, treatments between 160 and 180 kg N/ha showed statistically similar results, indicating scope for economic optimisation of nitrogen in sorghum cultivation under the tropical South Odisha conditions during the Rabi season.