不同秸秆还田方式对土默川平原灌区土壤细菌群落的影响

Effects of different straw returning methods on soil bacterial community in Tumochuan Plain irrigation area

【目的】探索不同秸秆还田方式对土默川平原灌区土壤细菌群落的影响。【方法】设置深松混耙秸秆还田(SSR)、条深旋秸秆还田(SCR)、深翻粉碎秸秆还田(DPR)和免耕秸秆覆盖还田(NTR)4个处理,以当地农户浅旋秸秆离田(CK)为对照,开展不同秸秆还田方式定位试验,采用16S rDNA扩增子高通量测序技术研究土壤微生物群落多样性,并分析其与土壤物理化学特性以及酶活性等关键环境因子间的相关性。【结果】不同秸秆还田方式显著影响土壤细菌多样性及群落结构(P<0.05);NTR处理显著增加了芽单胞菌门和厚壁菌门丰度(P<0.05),DPR处理中绿弯菌门丰度显著提高(P<0.05)、放线菌门丰度降低;各秸秆还田处理可显著改善土壤物理化学特性,提高土壤酶活性,其中SSR处理效果最显著。RDA分析发现,驱动土壤细菌群落组成的主要物理化学特性为碱解氮、速效钾、阳离子交换量、紧实度和容重,Arthrobacter、Gaiella、Solirubrobacter、Streptomyces易受土壤环境因子的影响。【结论】秸秆还田对土默川平原灌区土壤细菌群落均有不同程度的促进作用。

【Objective】To explore the effects of different straw returning methods on soil bacterial community in Tumochuan Plain irrigation area.【Methods】Four corn straw returning modes including subsoiling returning straw(SSR),deep spin returning straw(SCR),deep tillage returning straw(DPR),no-tillage returning straw(NTR),and farmer′s shallow rotation(CK)were the positioning tests.Soil bacterial community diversity was investigated by 16S rDNA amplicon high-throughput sequencing technology,and its correlation with soil physicochemical properties,enzyme activities were analyzed.【Results】There were significant effects in soil bacterial diversity and community composition among different straw returning treatments(P<0.05),in which,NTR treatment significantly enhanced the abundance of Gemmatimonadetes and Firmicutes(P<0.05),theabundance of Chloroflexi in DPR treatment was significantly increased(P<0.05),and the abundance of Actinobacteria was decreased.That the straw returing treatments could significantly improve the soil physicochemical properties and increase soil enzyme activities,among which SSR treatment had the most significant improvement effect(P<0.05).RDA analysis found that the main physicochemical properties that drive the composition of the soil bacterial community were alkaline hydrolysis nitrogen,available potassium,cation exchange capacity,compaction and bulk density,Arthrobacter,Gaiella,Solirorobacter,Streptomyces were susceptible to soil environmental factors.【Conclusion】The straw returning has a positive effect on the improvement of the soil biological community in the Tumochuan Plain irrigation area.