Long-term manuring increases microbial carbon use efficiency and mitigates priming effect via alleviated soil acidification and resource limitation

Autor: Wenju Zhang, Yaping Huang, Qiong Xiao, Qiqi Wang, Yanfang Tian, Lei Wu, Minggang Xu, Boren Wang
Rok vydání: 2021
Předmět:
Zdroj: Biology and Fertility of Soils. 57:925-934
ISSN: 1432-0789
0178-2762
DOI: 10.1007/s00374-021-01583-z
Popis: No fertilized soils (unfertilized and fallow treatments) and soils subjected to 28-year fertilization regimes, including mineral fertilization (PK and NPK) and manure amendments (NPKM and M), were incubated with or without 13C - glucose. Results showed that compared to mineral fertilization (0.64 − 0.69), the manure amendments significantly increased microbial C use efficiency (CUE) (0.76 − 0.79), mainly due to higher soil pH, lower resource stoichiometric ratios of dissolved organic C (DOC): mineral N, DOC: available P and mineral N: available P, and lower specific activities (per microbial biomass C unit) of β-1,4-glucosidase, N-acetyl-glucosaminidase and acid phosphatase. Glucose addition increased SOC mineralization, inducing positive priming effect (PE) with lower values in the manure amendments (0.11 − 0.12 mg C g−1 SOC) relative to mineral fertilization (0.25 − 0.55 mg C g−1 SOC). The PE was negatively correlated with soil pH and positively associated with resource stoichiometric ratios of DOC: mineral N, DOC: available P and mineral N: available P, mainly due to microbes mineralizing SOM to release nutrients, as indicated by the positive relationships between PE and the specific activities of N-acetyl-glucosaminidase and acid phosphatase. Concluding, relative to mineral fertilization, long-term manure amendment could increase CUE and decrease PE via alleviated soil acidification and resource limitation, thus facilitating soil C sequestration.
Databáze: OpenAIRE
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