Comparative analysis of maize–soybean strip intercropping systems: a review

Traditional maize (Zea mays L.) and soybean (Glycine max (L) Merrill) intercropping practice cannot be adapted to modern agriculture due to low light use efficiency, radiation use efficiency, low comparative profits of soybeans and incompatibility with mechanization. However, a new type of maize and soybean intercropping system (MSIS) with high land equivalent ratio (LER) provides substantial benefits for small-land hold farmers worldwide. Our research team has done a wide range of research to suggest the appropriate planting geometry that ensures high yield and LER as high as 2.36, nutrient acquisition and mechanical operations in MSISs. Increase in the distance between soybean and maize rows and decrease in the spacing of maize narrow rows is useful for the high light interception for the short soybean in MSISs. This review concludes that MSIS has multifold and convincing results of LER and compatible with mechanization, while those practiced other than China still require technological advancements, agronomic measures and compatible mechanization to further explore its adaptability.