设施尾菜高温闷棚还田对土壤微生物群落结构的影响

Effects of high temperature closed shed with vegetable returning on greenhouse soil microbial diversity and community structure

为了揭示设施尾菜高温闷棚还田对土壤微生物群落结构的影响,采用田间试验,研究了直接高温闷棚、尾菜还田后高温闷棚以及尾菜还田配施腐熟菌剂后高温闷棚处理对土壤化学性质、细菌和真菌群落结构及其代谢功能的影响。结果表明:直接高温闷棚显著降低活性有机碳含量,减少细菌多样性而增加真菌多样性。尾菜高温闷棚还田以及配施腐熟菌剂增加了土壤碱解氮和速效钾含量,但是均降低了真菌多样性指数。高温闷棚前后细菌和真菌群落结构均发生了显著的变化。闷棚后主要降低了Bacteroidota、Acidobacteriota和Crenarchaeota丰度,但是真菌Ascomycota丰度增加了16.42~34.01个百分点,且尾菜还田的增加幅度更大。闷棚后镰刀菌属丰度降低了1.46~7.03个百分点,而不闷棚则增加了0.46个百分点。与直接闷棚相比,尾菜高温闷棚还田或者添加腐熟菌剂降低了反硝化功能、氨化功能和硝态氮还原功能基因的相对丰度,而只有尾菜高温闷棚还田降低了碳氢化合物、芳香化合物和纤维素降解功能基因的相对丰度,配施腐熟菌剂则又增加了这3种相关功能基因的相对丰度。碱解氮是影响高温闷棚后土壤细菌和真菌群落结构的主要因子之一。由此可见,与直接高温闷棚相比,尾菜高温闷棚还田或者配施菌剂进一步改变了土壤微生物群落结构和相关碳氮代谢功能。

In order to reveal the effect of high-temperature closed shed with vegetable returning on greenhouse soil microbial community structure,the field experiments were carried out to study the effects of high-temperature treatments(direct high-temperature closed shed,high-temperature closed shed with vegetable returning and high-temperature closed shed after vegetable returning with composting agents,marking as T1,T2 and T3,respectively)on greenhouse soil chemical properties,bacterial and fungal community structure and metabolic function.The results showed that the direct high temperature closed shed significantly reduced the content of active organic carbon and bacterial diversity,but increased the fungal diversity.The soil alkali-hydrolyzable nitrogen and available potassium were increased by T2 and T3,but both the fungal diversity index were reduced.The community structure of bacteria and fungi changed significantly before and after high temperature closed shed.The abundance of Bacteroidota,Acidobacteriota and Crenarchaeota were decreased after closed shed,but the abundance of Ascomycota was increased by 16.42%-34.01%,and the greatest was obtained by high temperature closed shed with vegetable returning.The abundance of Fusarium was decreased by 1.46-7.03 percentage points after closed shed,but increased by 0.46 percentage points without closed shed.Compared with the direct closed shed,the relative abundance of denitrification function,ammonification function and nitrate nitrogen function genes reduced by the high temperature closed shed with vegetable returning or the addition of composting agents,while only the high temperature closed shed with vegetable returning reduced the relative abundance of hydrocarbon,aromatic compounds and cellulose degradation function genes,and the application of composting agents increased the relative abundance of these three related carbon metabolism functional genes.Alkali-hydrolyzable nitrogen was one of the main factors affecting the community structure of soil bacteria and fungi after high temperature closed shed.In conclusion,compared with the direct high temperature closed shed,the soil microbial community structure and related carbon and nitrogen metabolism functions were changed by high temperature closed shed with vegetable returning or the application of composting agents.