@article{fdi:010063898,
  title = {{S}table carbon isotope ratios in soil and vegetation shift with cultivation practices ({N}orthern {L}aos)},
  author = {{D}e {R}ouw, {A}nneke and {S}oulileuth, {B}. and {H}uon, {S}.},
  editor = {},
  language = {{ENG}},
  abstract = {{S}table carbon isotopes (delta {C}-13) can serve as a natural tracer of how plants contribute to soil organic pools ({SUM}). {T}he present study investigates whether a better knowledge of the vegetation could help to account more accurately for changes in {SOM}. {S}econdly it aims to identify environmental drivers for changes in the delta {C}-13 of {SOM}. {T}he study site was a small catchment where the initial forest had been cleared for agriculture in the 1960's. {T}he delta {C}-13 was determined in the surface vegetation and in {SOM} across 59 survey plots comprising fields and fallow land, 22 environmental and land use variables were also determined in the plots. {C}arbon isotope ratios in the {C}-3 pathway species (n = 209) ranged from -37.7 to -26.1 parts per thousand, in the {C}-4 species (n = 29) from -15.2 to -10.3 parts per thousand, in {SUM} from -28.1 to -22.6 parts per thousand. {C}ultivation of {C}-4 crops did not affect the delta {C}-13 of {SOM} suggesting that maize and {J}obs' tears residues supplied little {C}-4 material to {SOM}. {P}lots covered by a mix of {C}-3 and {C}-4 weeds had significant higher delta {C}-13 values in {SUM} than plots with only {C}-3 plants, suggesting that {C}-4 weeds more than {C}-4 crops contributed to {SOM}. {A}ccounting only for the perennials in the plot population gave strongest associations between {SUM} and vegetation. {A}lthough {C}-4 annual crops and {C}-4 annual weeds often cover the soil extensively during cultivation years, their biomass contribution to {SUM} is therefore much less than perennial {C}-4 plants occupying the site for longer periods. {S}oil delta {C}-13 increased significantly with short fallow periods in between cultivation years which can be explained by our finding that very short fallow periods were associated with the invasion of {C}-4 weeds. {C}ompetition with {C}-4 weeds in turn pushed the farmers to cultivate hardier crops like maize and {J}obs tears, replacing rain fed rice.},
  keywords = {{S}oil organic matter ; {C}-4 {C}rop{S} ; {C}-4 weeds ; {S}lash-and-burn ; {C}oppice ; {P}article-size fractions ; {LAOS}},
  booktitle = {},
  journal = {{A}griculture {E}cosystems and {E}nvironment},
  volume = {200},
  numero = {},
  pages = {161--168},
  ISSN = {0167-8809},
  year = {2015},
  DOI = {10.1016/j.agee.2014.11.017},
  URL = {https://www.documentation.ird.fr/hor/fdi:010063898},
}