Li Xiushuang, Chen Juan, Shi Jianglan, Tian Xiaohong
Key Laboratory of Land Resources Evaluation and Monitoring in Southwest, Ministry of Education/College of Geography and Resource Science, Sichuan Normal University, Chengdu 610068, China.
College of Natural Resources and Environment, Northwest A&F University/Key Lab of Plant Nutrition and the Agri-Environment in Northwest China, Ministry of Agriculture and Rural Affairs, Yangling 712100, China.
Plants (Basel). 2025 Aug 9;14(16):2476. doi: 10.3390/plants14162476.
To revive the practice of planting legume green manure (GM) in the fallow period in rainfed agricultural areas, it is essential to demonstrate the benefits of this practice on the yields and water use efficiency (WUE) of subsequent crops, especially when integrating with optimized water and fertilizer management. We conducted a field experiment to determine the positive effects of planting legume GM in the summer fallow on the yield, WUE, and nitrogen uptake efficiency (NupE) of subsequent winter wheat, which was grown with plastic film mulching and integrated fertilization in the Loess Plateau of China. A split-plot-designed experiment was arranged with two main treatments, namely (1) wheat planting followed by GM planting in the summer fallow (GM) and (2) conventional wheat monoculture followed by bare land summer fallow (BL), and three sub-treatments: (1) control treatment without any chemical fertilizer (Ct), (2) application of chemical N, P, and K as basal fertilizer (B), and (3) application of basal fertilizer plus wheat straw return (BS). In the initial two years, even in a dry year, GM did not decrease the soil water content and storage (0-200 cm layer) during the subsequent winter wheat season, relative to BL. But in the third and fourth years, GM increased the grain yield of winter wheat by 3.2% and 3.8%, respectively. B and BS increased the grain yield of winter wheat by 14.4% and 22.2%, respectively, during the third experimental year, and by 12.7% and 19.4% during the fourth experimental year, primarily through increasing the population density of winter wheat. The increase in the grain yield contributed to a higher WUE of winter wheat. In the third year, GM increased the water consumption (WC) and WUE of wheat by 2.4% and 1.7%, respectively, though they were far lower than B (8.3% and 5.6%) and BS (10.4% and 10.7%). B and BS resulted in a higher yield and N nutrition than GM alone, but GM combined with B and BS resulted in the highest yield and N nutrition, thus greatly decreasing the NupE and increasing N productivity. Planting legume GM in the fallow can further increase the long-term yield, WUE, and N utilization of winter wheat when integrated with chemical fertilization and wheat straw return in rainfed agriculture. Our study yields new insights into the agronomic benefits of legume GM application in semi-arid or analogous rainfed agroecosystems and underscores the critical role of water conservation in ensuring dryland agricultural production, particularly in regions undergoing optimization of fertilization.
为了恢复雨养农业区休耕期种植豆科绿肥的做法，必须证明这种做法对后续作物的产量和水分利用效率（WUE）的益处，特别是在与优化的水肥管理相结合时。我们进行了一项田间试验，以确定在中国黄土高原夏季休耕期种植豆科绿肥对后续冬小麦产量、水分利用效率和氮吸收效率（NupE）的积极影响，冬小麦种植采用地膜覆盖和综合施肥。试验采用裂区设计，有两个主处理，即（1）冬小麦种植后夏季休耕期种植绿肥（GM）和（2）传统冬小麦单作后夏季裸地休耕（BL），以及三个副处理：（1）不施任何化肥的对照处理（Ct），（2）施用化学氮、磷、钾作为基肥（B），（3）施用基肥加小麦秸秆还田（BS）。在最初两年，即使在干旱年份，与BL相比，GM在后续冬小麦季期间也没有降低土壤含水量和贮水量（0 - 200厘米土层）。但在第三年和第四年，GM分别使冬小麦产量提高了3.2%和3.8%。在试验的第三年，B和BS分别使冬小麦产量提高了14.4%和22.2%，在第四年分别提高了12.7%和19.4%，主要是通过增加冬小麦的群体密度。产量的增加促成了冬小麦水分利用效率的提高。在第三年，GM分别使小麦的耗水量（WC）和水分利用效率提高了2.4%和1.7%，尽管远低于B（8.3%和5.6%）和BS（10.4%和10.7%）。B和BS比单独的GM带来更高的产量和氮素营养，但GM与B和BS结合导致产量和氮素营养最高，从而大大降低了氮吸收效率并提高了氮生产力。在雨养农业中，将豆科绿肥种植与化肥施用和小麦秸秆还田相结合时，在休耕期种植豆科绿肥可以进一步提高冬小麦的长期产量、水分利用效率和氮素利用率。我们的研究为半干旱或类似雨养农业生态系统中应用豆科绿肥的农艺效益提供了新的见解，并强调了节水在确保旱地农业生产中的关键作用，特别是在施肥优化的地区。
