The Impact of Split Nitrogen Fertilizer Applications on the Productivity and Nitrogen Use Efficiency of Rice

The application of nitrogenous fertilizer in reduced (“split”) doses of its total is suggested as a means to increase nitrogen use efficiency and rice productivity whilst reducing its environmental impact. Field trials conducted in 2022 and 2023 aimed to assess the impact of split nitrogen fertilizer applications on the productivity and nitrogen use efficiency of rice. This experiment included three nitrogen treatments (N1: control (no nitrogen); N2: 50% basal + 25% at tillering stage + 25% at panicle initiation stage (conventional method); N3: 33.33% basal + 33.33% at tillering stage + 33.33% at panicle initiation stage (equal split of nitrogen)) and four high-yielding rice varieties (V1: Super Gold 2019; V2: Super Basmati 2019; V3: Noor Basmati 2017; V4: Kissan Basmati 2016). The results indicated that the N3 treatment, with an equal split of nitrogen, combined with the V4 variety (Kissan Basmati 2016) produced the most favorable outcomes. The results indicated that the N3 treatment, particularly when applied to Kissan Basmati (V4), produced, statistically, the highest leaf area index (32.98%, 29.59%), 1000-grain weight (32.84%, 46.97%), grain yield (30.02%, 38.09%), agronomic nitrogen use efficiency (9.21%, 11.63%), and partial factor productivity (29.98%, 38.11%) compared to the control for the study periods of 2022 and 2023, respectively. Moreover, the grain yield demonstrated a strong positive correlation with growth traits and other yield components, except for plant height. The results showed that the application of three equal nitrogen doses significantly increases rice production, and therefore, in this yield context, improves nitrogen use efficiency.