Legume‑based rotation increases soil phosphorus availability and enhances subsequent crop yields

• Published in: European journal of agronomy Vol. 170; p. 127707
• Main Authors: Chen, Zhen, Wang, Xin, Huang, Shou-Bing, Munz, Sebastian, Graeff-Hönninger, Simone, Hartung, Jens, Liang, Xiao-Gui, Shen, Si, Zhou, Shun-Li
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2025
• Subjects: Crop rotation; Legume inclusion; P fertilization; Soil P fractions; Yield; Soil P fractions; Yield; Legume inclusion; Crop rotation; P fertilization
• ISSN: 1161-0301
• DOI: 10.1016/j.eja.2025.127707

Sustainable agriculture is challenged by the intensive farming and phosphate scarcity. Crop rotation can greatly improve fertilizer use efficiency, especially with the inclusion of legumes. However, it remains unclear whether legume inclusion impacts soil phosphorus (P) cycling and crop P uptake under varying soil P conditions. Here, we used a five-year field experiment including four rotation systems: wheat-maize rotation alone introducing soybean as a grain legume, hairy vetch as a legume cover crop, and fallow into the wheat-maize rotation, each with and without P fertilization to investigate the effect on soil P fractions, activities of enzymes, and P uptake and yield of subsequent crops (wheat and maize). We found that the inclusion of hairy vetch and soybean increased wheat and maize yields compared with the maize-wheat rotation by 26.4 % and 14.8 % without P fertilization and, 8.9 % and 8.7 % with P fertilization. Including of hairy vetch resulted in higher soil Olsen-P in both P levels. Hairy vetch altered soil P fractions that were primarily affected by a large increase in the return of P from crop straw compared with other rotations. Including of hairy vetch increased soil labile P and moderately labile P by 43.4 % and 24.2 % without P fertilization, but only by 14.1 % for labile P with P fertilization, compared to the wheat-maize rotation. Structural equation modeling indicated that crop straw P return facilitated the transformation of non-labile P and moderately labile P into labile P via alkaline phosphatase (ALP) and microbial biomass P (MBP), particularly without P fertilization. Our results emphasize the vital role of legumes in improving soil P transformation and crop yield in crop rotations. [Display omitted] •Including legumes in rotation increase soil P availability and crop yields.•P fertilization repressed soil P cycling in rotation systems.•Crop straw P return improved soil P transformation to available P for the uptake by crops.