Abstract:

Based on the characteristics of controlled-release urea (CRU) and the nutrient uptake patterns of single-cropping late rice, this study developed a novel blended CRU formulation by optimizing the mixing ratio and release period of CRU and conventional urea (U), and investigated the feasibility of its one-time basal application as a substitute for conventional split fertilization. The aim was to provide a theoretical basis for achieving high yield, cost reduction, and enhancing efficiency in rice cultivation in Jiading District. Three treatments were established: T₁ (CRU:U = 75%:25% by mass, 30-day release period, one-time basal application), T₂ (conventional split application of U), and T₃ (no nitrogen application). Results showed that compared with T₂, the T₁ treatment significantly increased the SPAD value of flag leaves at flowering and milking stages by 3.56% and 17.38%, respectively, and increased panicles per unit area by 11.24%. Yield and net economic benefit were enhanced by 2.58% and 6.30%, respectively; aboveground nitrogen accumulation rose by 19.36%; while nitrogen use efficiency, agronomic efficiency, and partial factor productivity were significantly improved by 28.69%, 4.03%, and 2.58%, respectively. This one-time fertilization strategy enables multi-stage nitrogen supply through a single basal application, reduces fertilization frequency and labor costs, and increases nitrogen use efficiency by 9.53% compared with T₂ while maintaining stable yield. It represents an effective fertilization strategy suitable for the simplified and efficient cultivation of single-cropping late rice, demonstrating significant potential for cost reduction and efficiency improvement.

Key words: rice, controlled-release blended urea, nitrogen use efficiency, yield and economic benefit