Straw incorporation influences soil microbial diversity Metagenome

Straw incorporation is the most important measure to improve soil fertility and soil acidification. However, fresh straw that returned to the field cannot be decomposed in a short time. More accumulation of undecomposed straw in the soil change humus composition and the carbon structure. An experiment was designed to evaluate the effects of decomposed straw on soil fertility and microbial communities. Soil samples were collected from a region that was double rice seasons system with a single tobacco plantation in southwestern China. The soil was mixed with kinds of straw and incubated in a greenhouse. The responses of the soil fertility, microbial diversity and microbial population were analyzed after 0, 16, and 33 days of incubation. Overall, we found that: i) the soil organic matter and the organic carbon content of each humus component were significantly increased after 33 days of incubation. In addition, the condensation and oxidation degrees of the soil carbon structure was also decreased; ii) community dynamics changes in the soil were accompanied by changes of incubation times; iii) decomposed straw incorporation could stimulate potentially beneficial microbial populations; iv) decomposed straw incorporation with microbial agent application could be the best practice for the application of biofertilizers.