Chemical composition, or quality, of agroforestry residues influences N2O emissions after their addition to soil

N. Millar, Elizabeth Baggs

Research output: Contribution to journalArticle

78 Citations (Scopus)

Abstract

Emissions of N2O were measured following addition of N-15-labelled (2.6-4.7 atom% excess N-15) agroforestry residues (Sesbania sesban, mixed Sesbania/Macroptilium atropurpureum, Crotalaria grahamiana and Calliandra calothyrsus) to a Kenyan oxisol at a rate of 100 mg N kg soil(-1) under controlled environment conditions. Emissions were increased following addition of residues, with 22.6 mg N m(-2) (124.4 mg N m(-2) kg biomass(-1); 1.1 mg N-15 m(-2); 1.03% of N-15 applied) emitted as N2O over 29 d after addition of both Sesbania and Macroptilium residues in the mixed treatment. Fluxes of N2O were positively correlated with CO2 fluxes, and N2O emissions and available soil N were negatively correlated with residue lignin content (r = -0.49; P < 0.05), polyphenol content (r = -0.94; P < 0.05), protein binding capacity (r = -0.92; P < 0.05) and with (lignin + polyphenol)-to-N ratio (r = -0.55; P < 0.05). Lower emission (13.6 mg N m(-2) over 29 d; 94.5 mg N m(-2) kg biomass(-1); 0.6 mg N-15 m(-2); 0.29% of N-15 applied) after addition of Calliandra residue was attributed to the high polyphenol content (7.4%) and high polyphenol protein binding capacity (383 mug BSA mg plant(-1)) of this residue binding to plant protein and reducing its availability for microbial attack, despite the residue having a N content of 2.9%. Our results indicate that residue chemical composition, or quality, needs to be considered when proposing mitigation strategies to reduce N2O emissions from systems relying on incorporation of plant biomass, e.g. improved-fallow agroforestry systems, and that this consideration should extend beyond the C-to-N ratio of the residue to include polyphenol content and their protein binding capacity. (C) 2004 Elsevier Ltd. All rights reserved.

Original languageEnglish
Pages (from-to)935-943
Number of pages8
JournalSoil Biology and Biochemistry
Volume36
DOIs
Publication statusPublished - 2004

Keywords

  • agroforestry residues
  • lignin
  • nitrous oxide
  • polyphenols
  • protein binding capacity
  • residue quality
  • soil mineral N
  • NITROUS-OXIDE
  • DENITRIFICATION RATES
  • MINERALIZATION
  • RELEASE
  • LIGNIN
  • CARBON
  • LITTER
  • NITRIFICATION
  • DECOMPOSITION
  • INHIBITION

Cite this

Chemical composition, or quality, of agroforestry residues influences N2O emissions after their addition to soil. / Millar, N.; Baggs, Elizabeth.

In: Soil Biology and Biochemistry, Vol. 36, 2004, p. 935-943.

Research output: Contribution to journalArticle

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abstract = "Emissions of N2O were measured following addition of N-15-labelled (2.6-4.7 atom{\%} excess N-15) agroforestry residues (Sesbania sesban, mixed Sesbania/Macroptilium atropurpureum, Crotalaria grahamiana and Calliandra calothyrsus) to a Kenyan oxisol at a rate of 100 mg N kg soil(-1) under controlled environment conditions. Emissions were increased following addition of residues, with 22.6 mg N m(-2) (124.4 mg N m(-2) kg biomass(-1); 1.1 mg N-15 m(-2); 1.03{\%} of N-15 applied) emitted as N2O over 29 d after addition of both Sesbania and Macroptilium residues in the mixed treatment. Fluxes of N2O were positively correlated with CO2 fluxes, and N2O emissions and available soil N were negatively correlated with residue lignin content (r = -0.49; P < 0.05), polyphenol content (r = -0.94; P < 0.05), protein binding capacity (r = -0.92; P < 0.05) and with (lignin + polyphenol)-to-N ratio (r = -0.55; P < 0.05). Lower emission (13.6 mg N m(-2) over 29 d; 94.5 mg N m(-2) kg biomass(-1); 0.6 mg N-15 m(-2); 0.29{\%} of N-15 applied) after addition of Calliandra residue was attributed to the high polyphenol content (7.4{\%}) and high polyphenol protein binding capacity (383 mug BSA mg plant(-1)) of this residue binding to plant protein and reducing its availability for microbial attack, despite the residue having a N content of 2.9{\%}. Our results indicate that residue chemical composition, or quality, needs to be considered when proposing mitigation strategies to reduce N2O emissions from systems relying on incorporation of plant biomass, e.g. improved-fallow agroforestry systems, and that this consideration should extend beyond the C-to-N ratio of the residue to include polyphenol content and their protein binding capacity. (C) 2004 Elsevier Ltd. All rights reserved.",
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TY - JOUR

T1 - Chemical composition, or quality, of agroforestry residues influences N2O emissions after their addition to soil

AU - Millar, N.

AU - Baggs, Elizabeth

PY - 2004

Y1 - 2004

N2 - Emissions of N2O were measured following addition of N-15-labelled (2.6-4.7 atom% excess N-15) agroforestry residues (Sesbania sesban, mixed Sesbania/Macroptilium atropurpureum, Crotalaria grahamiana and Calliandra calothyrsus) to a Kenyan oxisol at a rate of 100 mg N kg soil(-1) under controlled environment conditions. Emissions were increased following addition of residues, with 22.6 mg N m(-2) (124.4 mg N m(-2) kg biomass(-1); 1.1 mg N-15 m(-2); 1.03% of N-15 applied) emitted as N2O over 29 d after addition of both Sesbania and Macroptilium residues in the mixed treatment. Fluxes of N2O were positively correlated with CO2 fluxes, and N2O emissions and available soil N were negatively correlated with residue lignin content (r = -0.49; P < 0.05), polyphenol content (r = -0.94; P < 0.05), protein binding capacity (r = -0.92; P < 0.05) and with (lignin + polyphenol)-to-N ratio (r = -0.55; P < 0.05). Lower emission (13.6 mg N m(-2) over 29 d; 94.5 mg N m(-2) kg biomass(-1); 0.6 mg N-15 m(-2); 0.29% of N-15 applied) after addition of Calliandra residue was attributed to the high polyphenol content (7.4%) and high polyphenol protein binding capacity (383 mug BSA mg plant(-1)) of this residue binding to plant protein and reducing its availability for microbial attack, despite the residue having a N content of 2.9%. Our results indicate that residue chemical composition, or quality, needs to be considered when proposing mitigation strategies to reduce N2O emissions from systems relying on incorporation of plant biomass, e.g. improved-fallow agroforestry systems, and that this consideration should extend beyond the C-to-N ratio of the residue to include polyphenol content and their protein binding capacity. (C) 2004 Elsevier Ltd. All rights reserved.

AB - Emissions of N2O were measured following addition of N-15-labelled (2.6-4.7 atom% excess N-15) agroforestry residues (Sesbania sesban, mixed Sesbania/Macroptilium atropurpureum, Crotalaria grahamiana and Calliandra calothyrsus) to a Kenyan oxisol at a rate of 100 mg N kg soil(-1) under controlled environment conditions. Emissions were increased following addition of residues, with 22.6 mg N m(-2) (124.4 mg N m(-2) kg biomass(-1); 1.1 mg N-15 m(-2); 1.03% of N-15 applied) emitted as N2O over 29 d after addition of both Sesbania and Macroptilium residues in the mixed treatment. Fluxes of N2O were positively correlated with CO2 fluxes, and N2O emissions and available soil N were negatively correlated with residue lignin content (r = -0.49; P < 0.05), polyphenol content (r = -0.94; P < 0.05), protein binding capacity (r = -0.92; P < 0.05) and with (lignin + polyphenol)-to-N ratio (r = -0.55; P < 0.05). Lower emission (13.6 mg N m(-2) over 29 d; 94.5 mg N m(-2) kg biomass(-1); 0.6 mg N-15 m(-2); 0.29% of N-15 applied) after addition of Calliandra residue was attributed to the high polyphenol content (7.4%) and high polyphenol protein binding capacity (383 mug BSA mg plant(-1)) of this residue binding to plant protein and reducing its availability for microbial attack, despite the residue having a N content of 2.9%. Our results indicate that residue chemical composition, or quality, needs to be considered when proposing mitigation strategies to reduce N2O emissions from systems relying on incorporation of plant biomass, e.g. improved-fallow agroforestry systems, and that this consideration should extend beyond the C-to-N ratio of the residue to include polyphenol content and their protein binding capacity. (C) 2004 Elsevier Ltd. All rights reserved.

KW - agroforestry residues

KW - lignin

KW - nitrous oxide

KW - polyphenols

KW - protein binding capacity

KW - residue quality

KW - soil mineral N

KW - NITROUS-OXIDE

KW - DENITRIFICATION RATES

KW - MINERALIZATION

KW - RELEASE

KW - LIGNIN

KW - CARBON

KW - LITTER

KW - NITRIFICATION

KW - DECOMPOSITION

KW - INHIBITION

U2 - 10.1016/j.soilbio.2004.02.008

DO - 10.1016/j.soilbio.2004.02.008

M3 - Article

VL - 36

SP - 935

EP - 943

JO - Soil Biology and Biochemistry

JF - Soil Biology and Biochemistry

SN - 0038-0717

ER -