Effects of rumen microorganisms on straw returning to soil at different depths

Slow decomposition of straw returning will lead to the aggravation of diseases and insect pests, affecting the growth of the next crop and causing the reduction of grain crops. This research was designed to investigate the effects of rumen microorganisms at different depths on straw returning to soil. By pot experiments finding, rumen microorganisms can accelerate straw decomposition. When straw returning to soil at 20 cm showed the best decomposition performance, which the straw degradation rate compared with the returning depth of 5, 10 and 30 cm, it has increased by 19.2%, 8.7% and 10.7%. At the optimal burial depth of 20 cm, the degradation rate of straw reached 46.4% on day 30, which 44.5% faster than that of the control. Moreover, the straw structure analysis proved that microorganisms derived from rumen fluids addition were conducive to destruction of functional groups and degradation of cellulose on straw surface. Additionally, it was demonstrated that rumen fluids could promote the rot of straw so that soil nutrients and enzyme activities were increased. According to high-throughput sequencing technology, the addition of rumen fluids significantly increased the abundance and diversity of soil microorganisms with strong straw decomposition ability, including bacteria and funguses. Experimental results provided an innovative approach for further development and utilization of rumen microorganisms. Most importantly, it provides new ideas for speeding up the straw returning.