Effects of maize and soybean intercropping on nodule growth, nitrogen fixation of soybean under low phosphorus condition

Abstract

To investigate the effects of maize and soybean intercropping on nitrogen and phosphorus uptake, nodule growth, and nitrogen fixation in soybean, a pot experiment was conducted with two phosphorus (P) rates (low P -P50 and sufficient P -P100). The results showed that, compared with monocropped soybean, intercropping of soybean and maize significantly increased the nodule number, nodule weight, leghemoglobin content, and nitrogenase activity of nodule, and promoted the growth and nitrogen (N) and phosphorus uptake of soybean under P50 and P100 rates. The concentrations of N, P, and the activities of acid phosphatase, phytase in nodules in intercropped soybean were significantly higher than those of monocropped soybean under P50 and P100 rates, and the activities of acid phosphatase and phytase showed the highest values under IS-P50 treatment. In addition, the P concentration in the nodules of intercropped soybean under P50 rate was significantly higher than that of monocropped soybean under P90 rate. so In summary, to maintain the larger phosphorus content for nitrogen fixation of soybean under phosphorus deficiency, the soybean and maize intercropping system increased the phosphorus concentration in the nodules mainly by enhancing the activities of acid phosphatase and phytase in the nodules, and thus promoted the growth and nitrogen uptake of soybean.