Changes in soil bacterial community structure and microbial function caused by straw retention in the North China Plain

The effects of straw retention on soil bacterial community structure, microbial function, and biochemical properties were assessed. Terminal restriction fragment length polymorphism (T-RFLP) and community-level physiological profile (CLPP) assays were used to assess the bacteria community structure and microbial function respectively. Treatments included straw removal with conventional tillage (CT), straw retention with conventional tillage (SRCT) and straw retention with no tillage (SRNT). SRCT and SRNT significantly (p < 0.05) increased soil organic carbon by 8.9% and 9.7%, and microbial biomass carbon by 44.7% and 330.8%, respectively, compared with CT. T-RFLP analysis indicated that straw retention had no favourable effect on soil bacterial diversity, and SRCT significantly (p < 0.05) decreased bacterial diversity compared to CT. Among the three treatments, SRNT had the highest activity of urease, invertase, cellulase, and beta-glucosidase. SRCT significantly (p < 0.05) increased the activity of invertase and beta-glucosidase compared to CT treatment. CLPP analysis showed that microbial functional diversity was significantly (p < 0.05) increased by straw retention. Enzyme activity and microbial functional diversity were not correlated with bacterial diversity. Therefore, according to this study, SRNT is a better farming practice because it improves soil fertility and biological quality.