中国科学院水利部水土保持研究所机构知识库

Fertilization is a worldwide practice to maintain and increase crop productivity and improve soil quality in agricultural ecosystems.
The interactive mechanisms of long-term fertilization affecting the functional soil organic matter (SOM) fractions, microbial
community, and enzyme activities are unclear. We investigated the effects of manure and mineral fertilization on six SOM
fractions (non-protected, physically, chemically, biochemically, physical-chemically, and physical-biochemically protected),
microbial community structure, and enzyme activities based on a 35-year fertilization experiment. The combined application
of manure and mineral fertilizers (NPKM) increased the soil organic carbon (SOC) and total nitrogen (TN) in the biochemically
(28.6–43.9%) and physically (108–229%) protected fractions, compared to their content in the unfertilized soil (CK). The total
phospholipid fatty acid content, Gram(−) bacteria, and actinomycetes, as well as the activities of α-1,4-glucosidase, β-1,4-Nacetylglucosaminidase,
β-1,4-xylosidase, and cellobiohydrolase were highest under NPKM fertilization. The protected SOM
fractions (physical, biochemical, physical-chemical, and physical-biochemical) were closely related to microbial community
composition (accounting for 67.6% of the variance). Bacteria were sensitive to changes in the physically and biochemically
protected fractions, whereas fungi responded more to the changes in the chemically protected fraction. In summary, long-term
mineral and organic fertilization has a strong effect on microbial communities and activities through the changes in the functional
SOM fractions.