Nutritional Effects of Soybean Root Architecture in a Maize/Soybean Intercropping System

In the present study, two soybean genotypes differing in root architecture were employed to evaluate the effects of soybean root architecture on N and P nutrient status and crop growth in a maize/soybean intercropping system. The results showed that land equivalent ratio (LER), biomass and N/P content of crops significantly increased in the maize/soybean intercropping system. LER was also higher in maize intercropped with Baxi10, the soybean genotype with a shallow root system, than that in maize intercropped with Bendi2, the soybean genotype with a deep root system, indicating that soybean root architecture may play an important role in the maize/soybean intercropping system. The greater LER in the legume-grass intercropping system (such as the maize/soybean intercropping system) could be mainly attributed to the greater N uptake as indicated by the competition ratio of maize to soybean (CRms), while the differences in LER between maize intercropped with different soybean genotypes might have resulted from different soil P uptake. Soybean genotype with a shallower root system was advantageous not only for soil P uptake but also for N uptake by both crops.