@article{fdi:010064103,
  title = {{S}urface organic carbon enrichment to explain greater {CO}2 emissions from short-term no-tilled soils},
  author = {{C}haplot, {V}incent and {A}bdalla, {K}. and {A}lexis, {M}. and {B}ourennane, {H}. and {D}arboux, {F}. and {D}lamini, {P}. and {E}verson, {C}. and {M}c{H}unu, {C}. and {M}uller-{N}edebock, {D}. and {M}utema, {M}. and {Q}uenea, {K}. and {T}henga, {H}. and {C}hivenge, {P}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he impact of agricultural practices on {CO}2 emissions from soils needs to be understood and quantified to enhance ecosystem functions, especially the ability of soils to sequester atmospheric carbon ({C}), while enhancing food and biomass production. {T}he objective of this study was to assess {CO}2 emissions in the soil surface following tillage abandonment and to investigate some of the underlying soil physical, chemical and biological controls. {M}aize ({Z}ea mays) was planted under conventional tillage ({T}) and no-tillage ({NT}), both without crop residues under smallholder farming conditions in {P}otshini, {S}outh {A}frica. {I}ntact top-soil (0-0.05 m) core samples ({N} = 54) from three 5 x 15 m(2) plots per treatment were collected two years after conversion of {T} to {NT} to evaluate the short-term {CO}2 emissions. {D}epending on the treatment, cores were left intact, compacted by 5 and 10%, or had surface crusts removed. {T}hey were incubated for 20 days with measurements of {CO}2 fluxes twice a day during the first three days and once a day thereafter. {S}oil organic {C} ({SOC}) content, soil bulk density ({P}b), aggregate stability, soil organic matter quality, and microbial biomass and its activity were evaluated at the onset of the incubation. {CO}2 emissions were 22% lower under {NT} compared with {T} with {CO}2 emissions of 0.9 +/- 0.10 vs 1.1 +/- 0.10 mg {C}-{CO}(2)g{C}(-1) day(-1) under {NT} and {T}, respectively, suggesting greater {SOC} protection under {NT}. {H}owever, there were greater total {CO}2 emissions per unit of surface by 9% under {NT} compared to {T} (1.15 +/- 0.03 vs 1.05 +/- 0.04 g {C}-{CO}2 m(-2) day(-1)). {SOC} protection significantly increased with the increase in soil bulk density (r= 0.89) and aggregate stability (from 1.7 +/- 0.25 mm to 2.3 0.31, r = 0.50), and to the decrease in microbial biomass and its activity (r = -0.59 and -0.57, respectively). {I}n contrast, the greater {NT} {CO}2 emissions per m(2) were explained by top-soil enrichment in {SOC} by 48% (from 12.4 +/- 0.2 to 19.1 +/- 0.4 g kg(-1), r = 0.59). {T}hese results on the soil controls of tillage impact on {CO}2 emissions are expected to inform on the required shifts in agricultural practices for enhancing {C} sequestration in soils. {I}n the context of the study, any mechanism favoring aggregate stability and promoting {SOC} allocation deep in the soil profile rather than in the top-soil would greatly diminish soil {CO}2 outputs and thus stimulate {C} sequestration.},
  keywords = {{N}o-tillage ; {C}arbon dioxide ; {C}limate change ; {M}aize ; {S}mall holders ; {A}frica ; {AFRIQUE} {DU} {SUD}},
  booktitle = {},
  journal = {{A}griculture {E}cosystems and {E}nvironment},
  volume = {203},
  numero = {},
  pages = {110--118},
  ISSN = {0167-8809},
  year = {2015},
  DOI = {10.1016/j.agee.2015.02.001},
  URL = {https://www.documentation.ird.fr/hor/fdi:010064103},
}