Residue addition frequency influences respiration, microbial biomass and nutrient availability in soil amended with high and low C/N residue

• Bo Zheng ^[1] ; Petra Marschner ^[1]
  1. [1] University of Adelaide

     University of Adelaide

     Australia

     
• Localización: Journal of soil science and plant nutrition, ISSN-e 0718-9516, ISSN 0718-9508, Vol. 17, Nº. 1, 2017, págs. 1-13
• Idioma: inglés
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• Resumen

  • In previous studies, we showed that the C/N ratio of the first residue added influences soil respiration, microbial biomass and nutrient availability after the second residue addition which we refer to as legacy effect. The aim of the study was to investigate the effect of residue addition frequency on microbial activity and nutrient availability, and the legacy effect. In Part A, the effect of high C/N residue (H) addition frequency in the first 16 days (d) was studied by adding H to soil once (d0), twice (d0, 8) or four times (d0, 4, 8, 12) followed by 10 g kg-1 low C/N residue (L) on day 16. The influence of L addition rate was assessed in Part B by adding H once on day 0 followed by L added once (d16), twice (d16, 24) or four times (d16, 20, 24, 24, 28). Cumulative respiration, microbial biomass C, N and P, N and P availability from d0 to d15 were higher with L than H. Particularly with L, cumulative respiration, microbial biomass and nutrient availability compared to single addition were lower on d7 with residue added twice or four times, but higher on d15. In Part A, H added twice or four times from d0 to d15 compared to a single H addition followed by a single L addition on d16 increased cumulative respiration, microbial nutrient uptake and reduced N and P availability on d23, but had no effect on d32. In Part B, frequent L addition after d16 enhanced microbial nutrient uptake on d23 but reducing nutrient availability compared to single L addition. It can be concluded that residue addition frequency strongly influences soil respiration, microbial biomass and nutrient availability after addition of low C/N residue.