Farmyard manure applications stimulate soil carbon and nitrogen cycling by boosting microbial biomass rather than changing its community composition

作者：Qingxu Ma, Yuan Wen, Deying Wang, Xiaodan Sun, Paul W. Hill, A. J. Macdonald, David R. Chadwick, Lianghuan Wu, Davey L. Jones · 发表于：Soil Biology and Biochemistry · 年份：2020 · DOI：10.1016/j.soilbio.2020.107760 · 被引用次数：216 · 研究领域：Soil Carbon and Nitrogen Dynamics、Soil and Water Nutrient Dynamics、Plant nutrient uptake and metabolism

Land application of farmyard manure (FYM) is a widespread agronomic practice used to enhance soil fertility, but its long-term effects on soil microbial carbon (C) and nitrogen (N) cycling have not been investigated in detail. Topsoils (0–23 cm) and subsoils (23–38 cm) were collected from a field trial on a sandy-textured soil where FYM had been applied at high (50–25 t ha−1 yr−1, 28 yr) and low rates (10 t ha−1 yr−1, 16 yr), and compared to soil treated only with synthetic NPK fertilisers. The turnover rate of key components of soil organic matter (SOM; proteins, peptides, amino acids, cellulose, and glucose) were evaluated by 14C labelling and measuring cellobiohydrolase, β-glucosidase, β-1,4-N-acetylglucosaminidase, L-leucine aminopeptidase, protease, and deaminase activities, whereas gross NH4 + and NO3 − production and consumption were determined by 15N-isotope pool dilution. Microbial communities were determined using phospholipid fatty acid (PLFA) profiling. Our results indicate that long-term FYM addition significantly enhanced the accumulation of soil C and N, soil organic N (SON) turnover, exoenzyme activity, and gross NO3 − production and assimilation. Rates of protein, peptide, and amino acid processing rate were 169–248, 87–147, and 85–305 mg N kgDWsoil −1 d−1, respectively, gross NH4 + and NO3 − production and consumption were 1.8–5.8 mg N kgDWsoil −1 d−1, and the highest rates were shown under the high FYM treatment in topsoil and subsoil. The half-life of cell...