The yield performance of maize-soybean intercropping in the North China Plain: From 172 sites empirical investigation

Abstract

ContextTo reduce pressure on soybean imports, the Chinese government has implemented maize (Zea mays L.)-soybean (Glycine max(L.) Merr.) intercropping (MǁS). The initiative focuses on mechanized, large-scale agricultural areas in the northern plains, aiming to harvest extra soybean while maintaining maize yield. Research questionAlthough the high production potential of MǁS has been established in small-scale experiments, its effectiveness in large-scale mechanized settings on the plains has been less explored. Such oversight misses the complexities of intercropping in terms of field management and configuration that affect yield in large-scale scenarios. MethodsThe study evaluated the yield performance of 172 households in the North China Plain (NCP) engaging in both MǁS and maize monoculture. A hierarchical model was constructed to forecast the MǁS’s high-yielding potential based on the coupling level of field configuration and field management. ResultsFindings revealed that MǁS's total yield was only 1 % higher than monoculture. The principal impediment to total yield enhancement was the 10 %-20 % reduction (compared to monoculture) in intercropped maize yield. The inputs for fertilisers, herbicides, chemical control agents, diesel, machinery, and labor for MǁS were 16 %-156 % higher than for monoculture, highlighting significant field management challenges. The imbalance between labor and machinery inputs in weeding was the MǁS’s efficiency constraints. Field configuration-type factors contributed 50 % to yield, surpassing field management (23 %). Planting size emerged as the most pivotal factor influencing yield, followed by fertiliser application. Strategies such as controlling the planting scale to 11 ha, increasing the proportion of maize planted to 60 %, optimizing fertiliser and herbicide application (488 kg ha−1, 3 kg ha−1), and managing weed labor (27 h ha−1) were critical in reducing the intercropped maize yield reduction to 9 %, approaching levels observed in previous fine management experiments. Furthermore, these measures resulted in an increased in the extra soybean yield of 16–26 %. ConclusionsMǁS is therefore eligible for support in the NCP based on the application of yield improvement measures. SignificanceThis study underscores the yield performance of mechanized, large-scale MǁS, providing theoretical support in terms of yield for its promotion in the NCP.