Soil nutrient distribution is highly heterogeneous at the plant root system level because of the diversity of soil composition. The heterogeneity of soil nutrients plays an important role in determining plant community structure and function. Recently, research has shown that soil nutrient heterogeneity increases the importance of plant diversity in community productivity. However, knowledge on the mechanism behind this phenomenon is currently lacking. Soil nutrient heterogeneity affects plant root foraging behavior and individual growth, which in turn affects the community structure and function. Therefore, for a better understanding of why there is a positive relationship between plant diversity and community productivity under soil nutrient heterogeneity conditions, it is very important to explore how plant root interactions affect root foraging behavior. Because of the application of fertilizer and the complex community composition, soil nutrient heterogeneity should be more typical in a multi-cropping system than in natural or monoculture systems. Therefore in this study, a typical intercropping system of maize and potato was chosen as a case study, and a pot experiment was conducted. The crops were planted in large pots with controlled-release nitrogen fertilizer applied homogeneously or heterogeneously, and with or without root interaction. Root interaction was achieved by the classical method of target design. At the flowering stage, plant biomass and yield were measured and the relative interaction index (RII), root foraging precision (the ratio of root biomass between higher and lower nitrogen patch), and land equivalent ratio (LER) were calculated to explore the response characteristics of crop growth to nitrogen heterogeneity and root interaction. The results showed that root interaction increased the foraging precision for both crops (F=3.017, P=0.094), and increased the root: shoot ratio for potato under nitrogen heterogeneity (P=0.001), but reduced the root: shoot ratio for maize regardless of nitrogen distribution (F=4.781, P=0.039). Nitrogen heterogeneity significantly improved biomass production for both crops (P=0.021), increased the LER (F=4.171, P=0.064), and significantly decreased the RII values (F=5.636, P=0.026) under root interaction conditions. Nitrogen heterogeneity significantly reduced the root: shoot ratio of maize (F=4.273, P=0.049), but increased the root: shoot ratio of potato in root interaction conditions, and decreased it in no root interaction conditions. This study suggested that root interaction can stimulate plant foraging behavior, which could be a key reason for the increase in the importance of plant diversity in community productivity under soil nutrient heterogeneity conditions. The data also showed that the non-resource root interaction, but not the resource root interaction, stimulates plant foraging behavior, which is in accordance with the theory that plants can integrate information about nutrients and neighbors, or is related to species-specific pathogenic microorganisms. Studies on more species and different environments are required to investigate this further. Further study is also required on the effects of root foraging behavior stimulated by plant root interactions on other community functions, such as structure or stability. Finally, it is necessary to investigate the non-resource mechanisms of root interactions such as recognition between plants, which stimulate plant root foraging behavior.