AUTHOR=Song Xiuli , Tao Bo , Guo Jing , Li Jingjing , Chen Guofeng TITLE=Changes in the Microbial Community Structure and Soil Chemical Properties of Vertisols Under Different Cropping Systems in Northern China JOURNAL=Frontiers in Environmental Science VOLUME=6 YEAR=2018 URL=https://www.frontiersin.org/journals/environmental-science/articles/10.3389/fenvs.2018.00132 DOI=10.3389/fenvs.2018.00132 ISSN=2296-665X ABSTRACT=

The predominant cropping system and management practices play an important role in soil physico-chemical properties and microbiome composition and diversity. This study analyzed the changes in soil fertility and the microbial community in four soybean-based cropping systems over 12 years. Amplification subsequencing techniques were used to compare soil community structures among the systems and identify significant positive and negative fertility factors. Soybean cropping favored the accumulation of OM and the available N, K DTPA Fe, Mn, Zn and Cu contents in soil but not fixed available P. The WS and CS cropping systems were conducive to the fixed available P, but they consumed OM, DTPA K, and Zn. The SC exhibited the lowest soil bacterial and archaeal abundance and diversity but high fungal abundance and diversity. The dominant Proteobacteria in the SC were significantly positively correlated with soil DTPA Fe and Mn. The dominant Actinobacteria were positively correlated with available P, DTPA Cu and Mn. The FS cropping system contained 764 unique bacterial species, 724 unique fungal species and the highest relative abundance of Protista. The FS had high microbial diversity, with high relative abundances of Bacteroidetes and Zygomycota and a significantly lower relative abundance of Actinobacteria. The Bacteroidetes were significantly correlated with available N, OM and DTPA Fe and negatively correlated with available P and DTPA Cu. Zygomycota was negatively correlated with available P and DTPA Cu. In the CS and WS, the soil bacterial abundance and diversity were moderate. The dominant Acidobacteria was significantly negatively correlated with soil DTPA, Fe and Mn. The CS exhibited the lowest fungal abundance and diversity. Furthermore, the relative abundance of Ascomycota was significantly improved in the WS and significantly positively correlated with available P and DTPA Cu. Decreases in the available P, K, DTPA Cu, and Mn of Vertisols greatly affect microbial community structure, and these nutrients regulate bacterial and fungal abundance and diversity. Compared to the SC, the FS, WS, and CS had more balanced soil fertility and microbial stability, but diverse cropping systems are most conducive to soil productivity. These findings are of great relevance for protecting the ecological environment.