添加猪粪对不同施肥历史土壤细菌群落的影响

为探讨粪肥携带的微生物对土壤微生物的影响,以长期施用粪肥和化肥的土壤为研究对象,耦合传统微生物学培养方法和现代分子微生物学方法,分析了猪粪和灭菌猪粪对2种土壤的细菌数量、群落结构和热代谢活性的影响.结果表明,以9.0t/hm²的用量施入时,猪粪和灭菌猪粪对两种土壤中的可培养细菌数量以及细菌16S-rRNA拷贝数均无明显影响;土壤中的土著微生物对猪粪携带的外源细菌在土壤中定殖具有明显的抑制作用,将2种土壤灭菌后添加猪粪,可培养细菌平均数量较未灭菌土壤分别增加45.96和96.21倍.粪肥输入的化学物质未导致土壤细菌群落结构和相对丰度发生明显变化;而粪肥输入的外源细菌Marinilabiaceae、Porphyromonadaceae、Bacteroidale和Pseudomonadaceae则可以在长期施用化肥的土壤中定殖并对相应的细菌丰度造成影响,但是在长期施用粪肥的土壤中,这些细菌在最开始就被抑制.添加粪肥提高了长期施用化肥土壤的微生物热代谢活性,但对长期施用粪肥的土壤无明显影响.长期施用化肥的土壤受粪源细菌的影响较大,而长期施用粪肥的土壤对粪肥的敏感度降低,对粪肥携带的外源细菌的抑制作用增强.

Effects of pig manure on bacterial community in soils with long-term application of chemical fertilizer or manure

In order to explore the effect of bacteria carried by manure on soil microorganisms, and to determine whether the history of manure application has affected the response of soil microorganisms to manure application. Taking the soil with long-term application of pig manure and long-term application of chemical fertilizer as the research objects, manure and sterilized manure were added to these soils. CFU number of the culturable bacteria, abundance of 16S-rRNA gene, bacterial community composition and microbial thermal metabolic activity were measured. When pig manure was applied as 9.0t/hm², the fecal bacteria and chemical nutrients carried by manure had no significant effect on the CFU number of culturable bacteria and 16S-rRNA copies in both soils. In addition, the soil indigenous microorganisms could significantly inhibit the colonization of exogenous bacteria carried by manure; if the indigenous microorganisms in these two soils had sterilized and pig manure was added, the average number of culturable bacteria would increase by 45 and 96 times respectively. Nutrients input from manure did not cause significant changes in soil bacterial community structure and abundance; while exogenous fecal bacteria imported from manure could colonize in the soil with long-term application of chemical fertilizer and affect the corresponding bacterial abundance. However, less fecal bacteria colonize in the soil with long-term application of pig manure, they were inhibited in the early stages of soil entry. Similarly, the addition of manure increased the microbial metabolic activity of the long-term chemical fertilizer application soil, but had no significant effect on the long-term manure application soil. In summary, manure has a greater impact on bacteria community in the soil with long-term application of chemical fertilizer, while the history of long-term application of manure reduces the "sensitivity" of the soil to manure, and enhances the inhibitory effect on the exogenous bacteria carried by manure.