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

Qingxu Ma, Yuan Wen, Deying Wang, Xiaodan Sun, Paul W. Hill, Andy Macdonald, David R. Chadwick, Lianghuan Wu, Davey L. Jones

Research output: Contribution to journalArticle

Abstract

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 cellulose and glucose decomposition under the high FYM treatment were 16.4% and 31.0% lower than them in the synthetic NPK fertiliser treatment, respectively, indicating higher rates of C cycling under high manure application as also evidenced by the higher rate of CO2 production. This was ascribed to an increase in microbial biomass rather than a change in microbial community structure. Based on the high pool sizes and high turnover rate, this suggests that peptides may represent one of the dominant forms of N taken up by soil microorganisms. We conclude that long-term FYM application builds SOM reserves and induces faster rates of nutrient cycling by boosting microbial biomass rather than by changing its community composition.

Original languageEnglish
Article number107760
JournalSoil Biology and Biochemistry
Volume144
DOIs
Publication statusPublished - 1 May 2020

Fingerprint Dive into the research topics of 'Farmyard manure applications stimulate soil carbon and nitrogen cycling by boosting microbial biomass rather than changing its community composition'. Together they form a unique fingerprint.

  • Cite this