Intercropping and relay intercropping are used globally as sustainable practices, e.g., in China, India, Southeast Asia, Latin America, and Africa. These practices use land efficiently, are high-yield, and provide efficient control of weeds, diseases and pests [7, 8]. Environmental resources, such as heat and light, can limit cropping systems, but with sufficient contributions of these resources, annual crop harvests increase. Heat and light resources are used efficiently with the practices of intercropping and relay intercropping to increase land output. Maize-soybean intercropping is used in areas with two crops a year (or three crops), e.g., the Huang-Huai-Hai region and in northwest China , whereas in areas with one crop a year (or three crops in two years), e.g., in southwest China , maize-soybean relay intercropping is the practice. In relay intercropping systems, the behaviors of component crops differ from those in sole cropping, and the grain yield and NUE are also affected. In a previous study, relay intercropping with legumes significantly increased the N uptake of the subsequent crop, leading to a 30% increase in grain yield . Compared with the corresponding monocultures, overall nitrogen resources are used 30–40% more efficiently in legume-cereal intercropping . Maize-soybean relay intercropping increases farm land productivity (i.e., the land equivalent ratio of maize-soybean relay intercropping systems ranges from 1.61 to 1.59), in contrast to the monocultures . According to Yamane et al., the land equivalent ratio of relay intercropping is higher than that of double cropping in a legume cropping system .