Substituting soybean for summer maize with optimal nitrogen fertilization enhances subsequent wheat yield and nitrogen use efficiency in semi-humid regions
Luo, Haiqiang ; Liu, Gaoxiang ; Qi, Tianxiang ; Cui, Nan;Xie, Binglin ; Xiang, Yingzhou ; Liu, Enke; Meruyert, Medelbek ; Assiya, Ansabayeva ; Jia, Zhikuan ; Siddique, Kadambot H. M.; Zhang, Peng
SOIL & TILLAGE RESEARCH
DOI：10.1016/j.still.2025.106594
Abstract
Leguminous crops are beneficial for enhancing crop yields and agricultural sustainability. However, the impacts of legume crops with optimal nitrogen (N) fertilization on the subsequent crop yield and N use efficiency (NUE) are unclear. Thus, a two-year field experiment was conducted to explore the effects of three cropping systems (FW: fallow-wheat, SW: soybean-wheat, and MW: maize-wheat) and three N fertilization rates (N0: 0 kg N ha-1, N1: 125 kg N ha-1, and N2: 225 kg N ha-1) on the soil N accumulation, grain yield (GY), and N utilization during the winter wheat season in a semi-humid region. Our findings showed that the soil N accumulation, dry matter accumulation (DMA), GY, and NUE were highest for wheat under SW, where the GY and NUE for winter wheat were 19.29 % and 46.42 % higher than the average values under FW and MW, respectively (P < 0.05). In addition, the soil N accumulation and GY for winter wheat both increased significantly under FW and MW as the N fertilization rate increased (P < 0.05). However, with SW, there was no significant (P > 0.05) difference in the winter wheat GY under SWN1 compared with SWN2, but the residual soil N (NO3--N and NH4+-N) decreased by 16.59 % and NUE increased by 76.19 %. In conclusion, SW combined with reduced N fertilization in a double-cropping system can enhance the subsequent winter wheat yield and NUE in semi-humid regions by increasing the accumulation and supply of soil N.