Optimizing Irrigation Scheduling and Nitrogen Management for Improved Quality, Nutrient Uptake and Moisture Dynamics in Summer Fodder Sorghum (Sorghum bicolor L. Moench)

Abstract

Sorghum bicolor is a climate-resilient, dual-purpose crop vital for food and fodder security in arid regions, yet in India, its productivity is constrained by inadequate quality feed and suboptimal irrigation and nitrogen management, which are critical determinants of forage yield and nutritional quality. A field experiment was conducted during the summer season of 2021 at the Integrated Farming System Research Farm, Junagadh Agricultural University, Junagadh on clayey soil to evaluate the effects of irrigation scheduling and nitrogen levels on crude protein, fibre yield, nutrient uptake, and water use efficiency (WUE) of fodder sorghum. The experiment employed a split-plot design with three irrigation schedules (Irrigation water/cumulative pan evaporation (IW/CPE) ratios: 0.6, 0.8 and 1.0) and four nitrogen levels (60, 80, 100 and 120 kg N ha-1), each replicated four times. We hypothesized the data will give the chance to recognize the proper combination of irrigation and nitrogen that improve fodder quality and resource use efficiency. Findings showed that irrigation at 1.0 IW/CPE ratio notably increased crude protein content and yield, crude fibre yield, NPK content and uptake, as well as water consumption. However, the highest WUE was detected at the 0.6 IW/CPE ratio. Applying 120 kg N ha-1 resulted in high crude protein content and yield, crude fibre content and yield, PK content, N content and uptake, while also improving WUE. Irrigation schedules did not significantly impact crude fibre content or soil availability of N, P2O5 and K2O. The study revealed that the interaction effects between irrigation schedules and nitrogen levels on crude protein yield, crude fibre yield, NPK uptake and WUE was significant. The study recommends that irrigation at an IW/CPE ratio of 0.8 combined with 120 kg N ha⁻¹ (I₂N₄) significantly improved fodder quality and WUE of summer sorghum supporting better livestock productivity.