Methodical Nitrogen–Water Distribution System Enhances Rice Yield While Reducing Environmental Losses: Evidence from ¹⁵N Isotope Tracing

Complete authors：Zhiyuan Yang; Yu Li; Yuanqing Shi; Hongkun Xie; Binbin Liu; Chuanhai Shu; Qingyue Cheng; Song Chen; Lanpeng Wang; Qiqi Chen; Hongji Liuru; Zhengbo Peng; Zongkui Chen; Jun Ma; Yongjian Sun; Na Li

Agronomy, Vol. 16, Issue 8, Article number: 801 (2026), April 2026 (IF=3.400).

Abstract

This study developed and evaluated a Methodical Nitrogen–Water Distribution (MNWD) system, employing ¹⁵N isotopic tracing to quantify nitrogen fate under three management regimes: Farmer's Practice (FP), Nitrogen–Water Coupling (NWC), and MNWD. Two-year field experiments demonstrated that MNWD achieved yield increases of 9.01–15.60% over FP and 2.51–5.73% over NWC, while reducing nitrogen application by 20%. The nitrogen recovery efficiency of MNWD reached 52.9–56.6%, and leaching losses were reduced by 65.4% compared to FP. MNWD resulted in 34.0% lower N₂O emissions than NWC while achieving a 5.45–5.49 percentage-point higher nitrogen recovery efficiency. The MNWD system demonstrates a viable pathway for sustainable rice intensification by decoupling productivity gains from nitrogen input intensity.

Keywords：greenhouse gas mitigation; N-15 isotope tracing; nitrogen use efficiency; paddy rice; water-nitrogen regulation