Effects of Gramineous and Leguminous Crops on Soil Microbial Community Structure and Diversity

Different crops have varying effects on soil factors, and their associated microbial community compositions also differ. Currently, there is limited comparative research on crops with distant phylogenetic relationships, such as those between gramineous and leguminous species. In this study, a pot experiment combined with high-throughput sequencing was conducted to enable a detailed comparison of microbial communities and soil factors across four crops: wheat, soybean, and two maize varieties. Compared to leguminous crops, differences between gramineous crops may be relatively smaller. The results showed that among the gramineous and leguminous crops, soybean had the lowest effect on soil electrical conductivity (EC) and available phosphorus (AP) (121.68 ± 2.70, 34.74 ± 1.02). The dominant fungi and bacteria phyla were Ascomycota and Proteobacteria; both were most abundant in the ZD958 variety, at 75.12% and 30.47%, respectively. The fungal diversity of ZD958 was most similar to that of W998, whereas the bacterial diversity of XY335 more closely resembled that of SB13. EC and AP were the key factors influencing fungal community composition, while alkali-hydrolyzable nitrogen (AN) was the key factor affecting bacterial community composition. These findings provide a basis for further in-depth research.