施肥对我国黑土农田土壤微生物群落多样性影响的研究及展望

Effects of fertilization on soil microbial community diversity in Chinese arable black soils:research progress and prospects

东北黑土是珍贵的土壤资源,由于长期的重用轻养,农田黑土退化问题已是一个不争的事实。施肥是保持/提高黑土农田生产力、保障作物产量的一项重要的农艺措施。本文综述了长期施用有机肥、无机肥、有机无机肥配施,以及无机肥氮(N)、磷(P)、钾(K)及其不同的组合施肥对黑土农田土壤细菌、真菌、固氮菌、反硝化细菌等微生物的数量、群落alpha多样性和beta多样性等方面影响的最新研究进展。发现研究结果因试验地点、季节气候、试验处理、目标微生物种类、甚至研究者的采样年限而不同。多数研究发现,长期施用化肥,特别是氮肥显著地降低了细菌丰度和alpha多样性指数,但对真菌丰度和alpha多样性指数影响不显著。不同施肥明显改变了黑土微生物beta多样性,但这种改变是有限的,相同施肥处理没有驱动不同试验地点土壤微生物群落结构同质化演替,表明东北黑土微生物分布具有很强的地域性。对长期施用不同的无机肥研究发现,N素较P素和K素在驱动黑土农田土壤微生物群落变化上作用更为明显。在论述长期施用有机肥改变土壤微生物群落结构的同时,也阐述了有机肥施用带来潜在的抗生素抗性基因污染的生态风险及对抗性基因的阻控措施。文章最后总结了目前施肥影响黑土农田微生物研究中存在的不足之处,并提出5点未来应加强的研究建议。

Black soil of Northeast China is a precious soil resource.Due to long-term overuse without proper maintenance of its fertility,the degradation of arable black soils has been an indisputable issue.Fertilization is an important agronomic practice to maintain/improve the productivity of black soils and ensure crop yield.In this paper,the recent research progress on the influences of long-term application of organic fertilizer,inorganic fertilizer,combined application of organic and inorganic fertilizer,as well as the effects of inorganic fertilizer N,P,K and their combinations on microbial quantity,community alpha diversity and beta diversity of soil bacteria,fungi,diazotrophs and denitrifying bacteria in arable black soils were reviewed.We found that the various findings depend on the location of the experimental sites,the treatments,the types of targeted microorganisms,and even the sampling year.Most studies found that long-term application of chemical fertilizer,especially nitrogen fertilizer,significantly reduces bacterial abundance and alpha diversity index,but has no significant effect on fungal abundance and alpha diversity.Different fertilizations significantly change the microbial beta diversity in black soils,but this change is limited,and the same fertilization treatment does not drive the homogenous succession of soil microbial community structures across different sites,indicating that the distribution of microorganisms in black soils has strong regionalism.In the study of long-term application of different inorganic fertilizers,it was found that N is the most important nutrient driving the change of soil microbial community in arable black soils than P and K.In this paper,besides discussing the changes of soil microbial community structure caused by long-term application of organic fertilizer,the potential ecological risk of antibiotic resistance gene pollution caused by organic fertilizer application and the counter measures of resistance genes are also discussed.Finally,some problems and knowledge gaps regarding the effect of fertilization on microorgan-isms in arable black soils are summarized,and the five future research comments are proposed.