Long‐term continuous cropping affects ecoenzymatic stoichiometry of microbial nutrient acquisition: a case study from a Chinese Mollisol

Journal Article · 03 June 2021 · Journal of the Science of Food and Agriculture

DOI: https://doi.org/10.1002/jsfa.11304 · OSTI ID:1786256

Chen, Xu ^[1]; Han, Xiaozeng ^[1]; Lu, Xinchun ^[1]; Yan, Jun ^[1]; Biswas, Asim ^[2]; Zou, Wenxiu  ^[1]

---

1. Key Laboratory of Mollisols Agroecology Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences Harbin China
2. School of Environmental Sciences University of Guelph Ottawa ON Canada

Abstract BACKGROUND Soil‐ and plant‐produced extracellular enzymes drive nutrient cycling in soils and are assumed to regulate supply and demand for carbon (C) and nutrients within the soil. Thus, agriculture management decisions that alter the balance of plant and supplemental nutrients should directly alter extracellular enzyme activities (EEAs), and EEA stoichiometry in predictable ways. We used a 12‐year experiment that varyied three major continuous grain crops (wheat, soybean, and maize), each crossed with mineral fertilizer (WCF, SCF and MCF, respectively) or not fertilized (WC, SC and MC, respectively, as controls). In response, we measured the phospholipid fatty acids (PLFAs), EEAs and their stoichiometry to examine the changes to soil microbial nutrient demand under the continuous cropping of crops, which differed with respect to the input of plant litter and fertilizer. RESULTS Fertilizer generally decreased soil microbial biomass and enzyme activity compared to non‐fertilized soil. According to enzyme stoichiometry, microbial nutrient demand was generally C‐ and phosphorus (P)‐limited, but not nitrogen (N)‐limited. However, the degree of microbial resource limitation differed among the three crops. The enzymatic C:N ratio was significantly lower by 13.3% and 26.8%, whereas the enzymatic N:P ratio was significantly higher by 9.9% and 42.4%, in MCF than in WCF and SCF, respectively. The abundances of arbuscular mycorrhizal fungi and aerobic PLFAs were significantly higher in MCF than in WCF and SCF. CONCLUSION These findings are crucial for characterizing enzymatic activities and their stoichiometries that drive microbial metabolism with respect to understanding soil nutrient cycles and environmental conditions and optimizing practices of agricultural management. © 2021 Society of Chemical Industry.

• Sponsoring Organization: USDOE
• OSTI ID: 1786256
• Journal Information: Journal of the Science of Food and Agriculture, Journal Name: Journal of the Science of Food and Agriculture Journal Issue: 15 Vol. 101; ISSN 0022-5142
• Publisher: Wiley Blackwell (John Wiley & Sons)Copyright Statement
• Country of Publication: United Kingdom
• Language: English