@article{fdi:010090274,
  title = {{C}over crops do not increase soil organic carbon stocks as much as has been claimed : what is the way forward ?},
  author = {{C}haplot, {V}incent and {S}mith, {P}.},
  editor = {},
  language = {{ENG}},
  abstract = {{W}hen compared to virgin land (forest and grassland), croplands store significantly lower amounts of organic carbon ({OC}), mainly as a result of soil tillage, and decreased plant inputs to the soil over the whole year. {D}oubts have been expressed over how much reduced and zero tillage agriculture can increase {OC} in soils when the whole soil profile is considered. {C}onsequently, cover-crops that are grown in-between crops instead of leaving soils bare appear as the "last man standing" in our quest to enhance cropland {OC} stocks. {D}espite the claim by numerous meta-analyses of a mean carbon sequestration rate by cover crops to be as high as 0.32 +/- 0.08 ton {C} ha(-1) year(-1), the present analysis showed that all of the 37 existing field studies worldwide only sampled to a depth of 30 cm or less and did not compare treatments on the basis of equivalent soil mass. {T}hirteen studies presented information on {OC} content only and not on {OC} stocks, had inappropriate controls (n = 14), had durations of 3 years or lower (n = 5), considered only one to two data points per treatment (n = 4), or used cover crops as cash crops (i.e., grown longer that in-between two crops) instead of catch crops (n = 2), which in all cases constitutes shortcomings. {O}f the remaining six trials, four showed non-significant trends, one study displayed a negative impact of cover crops, and one study displayed a positive impact, resulting in a mean {OC} storage of 0.03 ton ha(-1) year(-1). {M}odels and policies should urgently adapt to such new figure. {F}inally, more is to be done not only to improve the design of cover-crop studies for reaching sound conclusions but also to understand the underlying reasons of the low efficiency of cover crops for improved carbon sequestration into soils, with possible strategies being suggested.},
  keywords = {land management ; organic matter ; quality soil},
  booktitle = {},
  journal = {{G}lobal {C}hange {B}iology},
  volume = {29},
  numero = {},
  pages = {6163--6169},
  ISSN = {1354-1013},
  year = {2023},
  DOI = {10.1111/gcb.16917},
  URL = {https://www.documentation.ird.fr/hor/fdi:010090274},
}