Effects of straw mulching on soil nutrient content and microbial community on the gentle slope arable land in dryland farming

Straw mulching (SM) is recognized as an effective management practice to alter soil nutrient translocation on the gentle slope arable land. The objective of this work was to evaluate the effects of straw mulching on soil nutrient content and microbial community. The two-year experiment involved six treatments: experiment slopes (3, 6, and 9 degrees, 20 m long) and mulching (i.e. only maize straw (1.65 kg m(-2)) was mulched, and no mulch). Straw mulching treatments increased the levels of soil available nitrogen (AN), total nitrogen (TN), available phosphorus (AP), and total phosphorus (TP) at three different soil slopes. The AN content for 9 degrees slopes straw mulching (NS) was 69.4% higher than 9 degrees slopes no straw mulching (N), and also enhanced bacterial richness and diversity. The relative abundance of Proteobacteria and Bacteroidetes for NS were 48.3% and 76.7% larger than N treatment, respectively. Ascomycota was higher in 6 degrees slopes straw mulching (55.3%) followed by NS (53.5%). In all, our findings showed that the application of straw mulching was a better approach for the restoration of slopy arable land (especially in arable land with high slope) fertility based on enhancing soil nutrient and microbial community.