Original Research ARTICLE
Nematodes and Microorganisms Interactively Stimulate Soil Organic Carbon Turnover in the Macroaggregates
- 1State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, China
- 2University of Chinese Academy of Sciences (UCAS), China
- 3College of Resources and Environmental Sciences, Nanjing Agricultural University, China
The intra-aggregate architecture of soil macroaggregates provides suitable microhabitats for nematodes to graze on microorganisms. However, it is not fully disentangled how nematodes and microbial communities interactively mediate soil organic carbon (SOC) turnover. Here, we aimed to illustrate the relationships between nematodes, microbial community, and SOC turnover in the macroaggregates of a red soil receiving long-term manure application. Soil macroaggregates (> 2 mm) were sampled from an 11-year field experiment including four manure treatments: no manure (M0), low manure rate (M1), high manure rate (M2), and high manure rate with lime (M3). The abundances of nematodes and microbial communities were substantially increased under manure treatments. Bacterivores dominated under the M2 and M3 treatments, while plant parasites were enriched under the M1 treatment. Phospholipid fatty acid analysis indicated that the ratio of bacteria to fungi significantly increased but the ratio of Gram-positive bacteria to Gram-negative bacteria declined with the increasing manure addition. Random forest modelling showed that soil porosity had a primary effect on the nematode assemblages, while pH and SOC contributed profoundly to the microbial community structure and carbon metabolic capacity. Structural equation modelling suggested that nematode grazing promoted carbon metabolic activities predominantly due to increased microbial biomass. Taken together, the mechanistic understanding of nematode-microorganism interactions may have important implications for improving soil fertility by nematode-mediated microbial processes.
Keywords: Nematode assemblages, microbial community, Porosity, nutrient availability, carbon metabolic activities, Soil organic carbon turnover, Soil macroaggregates
Received: 31 Aug 2018;
Accepted: 31 Oct 2018.
Edited by:Stefan Geisen, Netherlands Institute of Ecology (NIOO-KNAW), Netherlands
Reviewed by:Ye Deng, Research Center for Eco-environmental Sciences (CAS), China
Rutger A. Wilschut, Netherlands Institute of Ecology (NIOO-KNAW), Netherlands
Copyright: © 2018 Jiang, Zhou, Chen, Fang, Luan, Chen, Wang, Liu, Li, Peng and Sun. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. Bo Sun, State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, Jiangsu Province, China, email@example.com