Long-term fertilization shapes the size and community composition of the soil food web by altering resource quantity and quality. While previous studies have examined specific components; however, comprehensive effects on the entire food web and underlying mechanisms remain unclear.
To solve the problem, a team of researchers from China conducted a 30-year experiment in a rice–wheat cropping system to assess the effects of chemical fertilizer (NPK), manure (M), and their combination (NPKM), with unfertilized soil as the control. They published their findings in the Journal of Integrative Agriculture .
“We measured biomass or abundance across key taxonomic and functional groups, including microorganisms, protozoa, nematodes, mites, collembolans, enchytraeids, and earthworms and calculated nematode ecological indices to evaluate bottom-up and top-down regulatory influences,” explains first and corresponding author Prof. Yunfeng Chen from Hubei Academy of Agricultural Sciences.
The team's results showed that long-term fertilization increased resource inputs, thereby enhancing most functional groups. “M and NPKM outperformed NPK across most groups, with relative increases compared to NPK ranging from 20.69 to 972.52% under M (average: 241.62%) and from 26.55 to 792.30% under NPKM (average: 189.02%),” says Chen.
However, differences between M and NPKM were not significant, as high soil fertility diminished the divergence in their effects. “Strong evidence for bottom-up control was observed, supported by positive correlations among functional groups and by increases in the enrichment index (51.27 and 28.49%) and enrichment footprint (11.80 and 47.17%) under M and NPKM relative to NPK,” adds Chen.
Partial least squares path modeling further confirmed that bottom-up forces predominantly determined food web structure and biomass.
“These findings indicate that sustained organic inputs, particularly when integrated with mineral fertilizers, effectively enhance soil food web complexity and size primarily through bottom-up regulatory mechanism,” says Chen.
###
Contact Authors:
Correspondence Yunfeng Chen, Tel: +86-27-88430582, E-mail: chen971314@ 163.com
The publisher KeAi was established by Elsevier and China Science Publishing & Media Ltd to unfold quality research globally. In 2013, our focus shifted to open access publishing. We now proudly publish more than 200 world-class, open access, English language journals, spanning all scientific disciplines. Many of these are titles we publish in partnership with prestigious societies and academic institutions, such as the National Natural Science Foundation of China (NSFC).
Journal of Integrative Agriculture
Long-term fertilization enriches soil food web mainly through bottom-up regulation in a rice–wheat cropping system
The authors declare that they have no conflict of interest.