Soybean roots and soil amendments can help improve the health of soil contaminated with cadmium. By adding a soil conditioner called CMC, the pH of the soil increased and the harmful cadmium levels decreased. This led to a reduction in cadmium accumulation in soybean grains. The application of CMC also affected different microbial communities in the soil, with some diversity changes observed. Certain key groups of bacteria, fungi, arbuscular mycorrhizal fungi, and nematodes were found to be important for soil health. The soil amendment helped suppress harmful pathogens and made the bacterial community more resistant to cadmium stress. Overall, using CMC in contaminated soil can enhance soil functions and health.