稻田周丛生物对小麦秸秆腐解和养分释放的影响OA

Straw returning is an important measure to improve soil fertility,but the returned straw has long decompo-sition cycle and high carbon loss rate.To clarify the effect of periphyton on the decomposition process of wheat straw in rice-wheat rotation system in the middle and lower reaches of the Yangtze River,this study analyzed the effects of periphyton on wheat straw decomposition rate,nutrient re-lease rate and soil carbon content and nitrogen content by setting straw returning treatment(S),periphyton treat-ment(PB)and straw returning+periphyton treatment(SPB).The results showed that the rapid decomposition period of wheat straw treated with SPB was five days longer than that of S treatment.After 40 days of treatment,the cumulative decomposition rate of wheat straw treated with SPB was 7.84%higher than that of S treatment,but there was no significant difference in the decomposition rate of wheat straw after 130 days of treatment.The cumulative carbon release rate of wheat straw(0-60 d)in SPB treatment was higher than that in S treatment.After 40 days of decomposition,the cumulative carbon release rate of wheat straw in SPB treatment was 4.61 percentage points higher than that in S treatment.The cumulative release rate of straw nitrogen(30-60 d)in SPB treatment was lower than that in S treatment.After 40 days of decomposition,the cumulative release rate of straw nitrogen in SPB treatment decreased by 2.15 percentage points compared with S treatment.After 130 days of straw decomposition,the soil total organic carbon content of SPB treatment was 9.54%higher than that of S treatment.After 20 days of straw decom-position,the relative abundance of Bacillus subtilis and cellulase activity in SPB treatment were significantly higher than those in S treatment.The results of this study showed that periphyton could promote the rapid decomposition of straw,accelerate the release of carbon in the early stage of decomposition,slow down the release of nitrogen in the middle stage,and increase the fixation and utilization of straw nutrients.