Interactive effects of field mulching and nitrogen management on leaf photochemical efficiency, water use, and yield formation in winter oilseed rape (Brassica napus L.): A three-year appraisal

作者：Zijun Tang, Zhijun Li, Youzhen Xiang, Junhua Wang, Sabeeqa Usman Malik, Tao Sun, Jun‐Sheng Lu, Wei Zhang, Shunli Wang, Xueyan Zhang, Fucang Zhang · 发表于：Agricultural Water Management · 年份：2025 · DOI：10.1016/j.agwat.2025.110083 · 被引用次数：6 · 研究领域：Nitrogen and Sulfur Effects on Brassica、Irrigation Practices and Water Management、Plant Stress Responses and Tolerance

In arid and semi-arid regions, optimizing field mulching and nitrogen (N) management is crucial for winter oilseed rape production. This three-year study on the Chinese Loess Plateau investigated how mulching modes (film, straw, and no mulching) and N rates interact to influence yield and water productivity through coupled water–light–carbon processes. We developed a coupled "water–light" efficiency index to diagnose leaf physiological status and applied structural equation modeling to quantify driving mechanisms. Results showed that film mulching combined with moderate N (210 kg ha −1 ) achieved a robust seed yield of 3762.7 kg ha −1 , comparable to the highest N rate but with 25 % less fertilizer input, while attaining superior water productivity of 10.83 kg ha −1 mm −1 . Mechanistically, film mulching acted as a hydrological regulator by reducing evaporation and stabilizing root-zone soil water. This favorable environment allowed moderate N to function as a physiological activator, enhancing leaf chlorophyll content and photochemical efficiency without the excessive water depletion often caused by high N inputs. The proposed coupled index effectively captured this synergy, identifying physiological states with "low water cost and high photochemical return." Structural modeling confirmed that yield formation was driven by a cascade where stabilized soil water promoted leaf physiological function and canopy structure, ultimately maximizing carbon assimilation. Consequently, ...