Synergizing root growth and carboxylate release enhance seed yield in maize-soybean intercropping on acidic karst soils
| 作者 | Cheng-Xi Yi a,1, Yi Jin b,1, Long-Gui Li a, Yu-Mei Wang a, Yu Dai a, Qiao Zhu a, Xiao-Li Wang a, Yinglong Chen c, Xiao-Min Wu d, Jin He a,* , Sanwei Yang a |
| 刊物 | Field Crops Research |
| 标识符 | 10.1016/j.fcr.2025.110286 |
| 摘要 | Context: Southwest China is one of the largest karst regions, where nitrogen (N) deficiency and poor management limit crop productivity. Maize-soybean intercropping is a widely adopted planting model used by farmers across China. Therefore, innovative crop management practices to improve productivity in this region are essential to ensure China’s food security. Objective and methods: Ridge-furrow with film mulching (RFM) combined with N supply was introduced for the first time into the maize-soybean intercropping system. Eight treatment combinations (maize and soybean monocultures (M), maize-soybean intercropping with RFM and with ridge-furrow (RF) under 0 (N0) and 150 (N150) kg N ha−1 supply) were used to investigate changes in seed yield, land use efficiency, biomass, N uptake, and root morphological and physiological traits from 2020 to 2023 in Southwest China. Results: The results showed that introduction of RFM into the maize-soybean intercropping system significantly increased maize (13 %) and soybean (42 %) seed yields and land equivalent ratio (LER) (25 %) compared to ridge-furrow without film mulching. Meanwhile, N150 significantly increased maize (33 %) and soybean (24 %) seed yields compared to N0 across four years. The high LER was attributed to the increased yields of maize and soybean, which were associated with higher biomass and N uptake under RFM. The promotion of root growth, such as increased root length and carboxylate release with RFM, enhanced N uptake in both maize and soybean was observed across three years (2021–2023). In addition, N application significantly increased biomass accumulation, N uptake, root length, and carboxylate release at two developmental stages across two years (2022and 2023), thus contributing to higher seed yields in maize and soybean. Conclusion: RFM combined with N supply can further increase crop yield and land use efficiency in maizesoybean intercropping systems in karst areas. This improvement is explained by the enhancement of the “Ncapture”, related to root morphological traits, and “N-mining”, related to carboxylate release, which together increase N uptake, biomass, and ultimately seed yield. Implications: RFM combined with N addition could be considered an efficiency strategy to increase crop productivity in maize-soybean intercropping systems in karst agroecosystems. Our results provided insights into the effects of crop management practices and N addition on N-acquisition strategies and their roles in nutrition uptake and yield formation. |
