2种还田模式下小麦秸秆腐解菌剂应用效果研究

Effects of Biodegradation Agents on Straw Degradation in Two Kinds of Straw Returning

为了研究2种不同还田模式下秸秆腐解菌剂的应用效果,选取北京大兴小麦—玉米常年轮作田当季小麦秸秆,使用自行研制秸秆腐解菌剂,考察了覆盖还田和翻压还田2种还田方式下,不同秸秆腐解菌剂对秸秆各组分的影响,并进一步分析了原位生物腐解还田小麦秸秆对土壤活性有机碳的影响。结果表明:翻压还田4周后,接种不同菌剂小麦秸秆纤维素降解速率为BW2≈BW3>BW1,分别比对照提高24.95%、24.57%、2.10%;翻压还田6周后,接种不同菌剂秸秆半纤维素降解速率为BW2>BW3>BW1,与对照相比分别提高12.67%、8.80%、1.47%。覆盖还田方式下,秸秆纤维素降解较翻压还田缓慢,还田4周小麦秸秆纤维素降解率为BW2>BW3>BW1,分别比对照提高26.52%、24.01%、21.02%;半纤维素在还田6周后降解明显,BW2>BW3>BW1,与对照相比分别提高22.90%、20.00%、9.32%。在2种还田方式中,腐解菌剂对小麦秸秆木质素降解能力有限,3种菌剂腐解效果差别不大。在秸秆翻压还田过程中复合菌剂BW2提升土壤活性有机碳含量最快,提升了54.09%;而在覆盖还田中复合菌剂BW3提升土壤活性有机碳较快,提升了34.58%。复合菌剂BW2和BW3在2种不同的还田模式下均能高效快速的降解秸秆,其中翻压还田模式比覆盖还田模式秸秆降解效果更好,并能显著提高土壤活性有机碳含量。

In order to study the effects of biodegradation agents in two kinds of straw returning（i.e.soil returning straw and mulching straw）,changes of wheat straw components by biodegradation agents were studied under field in two kinds of straw returning,meanwhile effect of decomposed wheat straw on soil labile carbon was also conducted.Wheat straw was from field under wheat-maize rotation system.Three biodegradation agents（i.e.BW1,BW2,BW3） were selected from our own laboratory.Results indicated that,under soil returning straw patterns cellulose-straw degradation rate was BW2 ≈ BW3 BW1 in four weeks,and the rate was increased by 24.95%,24.57%,2.10% compared with CK1.In six weeks,hemicellulose-straw degradation rate was BW2 BW3 BW1,increased by 12.67%,8.80%,1.47% than CK1.In the mulching straw patterns,cellulose-straw degraded relatively slow,cellulose-straw degradation rate was BW2 BW3 BW1 in four weeks,increased by 26.52%,24.01%,21.02% than CK1.Hemicellulose-straw contents were changed obviously,hemicellulose-straw degradation rate of three biodegradation agents was BW2 BW3 BW1,increased by 22.90%,20.00%,9.32% compared with CK1.No obvious differences happened in three biodegradation agents to the lignin-straw degradation rate during two patterns.In the process of soil returningstraw,the content of soil labile carbon was increased by 54.09% in biodegradation agent BW2 which was the highest.However,during mulching straw pattern,the content of soil labile carbon was increased by 34.58% in biodegradation agent BW3.Both the biodegradation agents BW2 and BW3 could degrade wheat straw high effectively in two patterns.It was found that microorganism agents by the soil returning straw patterns had better degradation effect,and the content of soil labile carbon was obviously increased.