ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

To investigate the changes in soil organic carbon (SOC), bacterial communities and metabolic functions, as well as the dynamic response relationships with each other in facility agricultural land with different cropping periods, organic carbon, bacterial community structure and metabolic functions in soil were systematically characterized in unplanted (CK), 0 to 5a (0~5a), 5a to 10a (5~10a), 10a to 20a (10~20a) and more than 20a (20a+) of continuous cropping by using temporal-spatial substitution method in a centralized area of facility agriculture in the southern suburb of Beijing as the study area. The dynamic response of SOC and its active components to the bacterial dominant communities and their interrelationships with bacterial metabolic functions were explored with redundancy analysis (RDA), typical correlation analysis (CCA), prediction of PICRUSt2 function, and Mantel test. Based on the results, continuous cropping caused the contents of microbial biomass carbon (MBC), easily oxidizes organic carbon (EOC), SOC and soil organic carbon density (SOCD) all showed an increasing and then decreasing trend with the increase of cropping period. Dissolved organic carbon (DOC) content was the highest at 20a+. Microbial entropy (Q) was decreased with the increase of cropping period. Continuous cropping decreased the diversity of soil bacteria and increased the differences among bacterial species. PICRUSt2 prediction showed that the functions of soil bacteria in different continuous cropping period were dominated by metabolism, and the abundance of secondary metabolism functions of bacteria was significantly higher in the soil from 5~20a than that in the soil from 0~5a, 20a+, and CK. Among the bacterial groups in the top 10 relative abundance, the Acidobacteriota were negatively correlated with both SOC and its active components. The key bacterial groups dominating and participating in SOC accumulation and cycling showed a shift from eutrophic to oligotrophic and pathogenic taxa after 20a+ of continuous cropping. Mantel analysis showed that a total of 53 classes of functions in the third tier were significantly correlated (p<0.05) with SOC and its components. Among them, totally 23 classes were affiliated to metabolic functions in the first tier, and as many as 51 classes were significantly correlated with EOC. The finding can provide scientific references for optimizing carbon cycle-related bacterial functional groups and enhancing the carbon sink function of small-scale facility agricultural soils.