@article{fdi:010071991,
  title = {{H}igh organic inputs explain shallow and deep {SOC} storage in a long-term agroforestry system - combining experimental and modeling approaches},
  author = {{C}ardinael, {R}. and {G}uenet, {B}. and {C}hevallier, {T}iphaine and {D}upraz, {C}. and {C}ozzi, {T}. and {C}henu, {C}.},
  editor = {},
  language = {{ENG}},
  abstract = {{A}groforestry is an increasingly popular farming system enabling agricultural diversification and providing several ecosystem services. {I}n agroforestry systems, soil organic carbon ({SOC}) stocks are generally increased, but it is difficult to disentangle the different factors responsible for this storage. {O}rganic carbon ({OC}) inputs to the soil may be larger, but {SOC} decomposition rates may be modified owing to microclimate, physical protection, or priming effect from roots, especially at depth. {W}e used an 18-year-old silvoarable system associating hybrid walnut trees ({J}uglans regia x nigra) and durum wheat ({T}riticum turgidum {L}. subsp. durum) and an adjacent agricultural control plot to quantify all {OC} inputs to the soil - leaf litter, tree fine root senescence, crop residues, and tree row herbaceous vegetation - and measured {SOC} stocks down to 2 m of depth at varying distances from the trees. {W}e then proposed a model that simulates {SOC} dynamics in agroforestry accounting for both the whole soil profile and the lateral spatial heterogeneity. {T}he model was calibrated to the control plot only. {M}easured {OC} inputs to soil were increased by about 40% (+ 1.11 t{C}ha(-1) yr(-1)) down to 2 m of depth in the agroforestry plot compared to the control, resulting in an additional {SOC} stock of 6.3 t{C}ha(-1) down to 1 m of depth. {H}owever, most of the {SOC} storage occurred in the first 30 cm of soil and in the tree rows. {T}he model was strongly validated, properly describing the measured {SOC} stocks and distribution with depth in agroforestry tree rows and alleys. {I}t showed that the increased inputs of fresh biomass to soil explained the observed additional {SOC} storage in the agroforestry plot. {M}oreover, only a priming effect variant of the model was able to capture the depth distribution of {SOC} stocks, suggesting the priming effect as a possible mechanism driving deep {SOC} dynamics. {T}his result questions the potential of soils to store large amounts of carbon, especially at depth. {D}eep-rooted trees modify {OC} inputs to soil, a process that deserves further study given its potential effects on {SOC} dynamics.},
  keywords = {{FRANCE}},
  booktitle = {},
  journal = {{B}iogeosciences},
  volume = {15},
  numero = {1},
  pages = {297--317},
  ISSN = {1726-4170},
  year = {2018},
  DOI = {10.5194/bg-15-297-2018},
  URL = {https://www.documentation.ird.fr/hor/fdi:010071991},
}