@article{fdi:010077428,
  title = {{O}rganic carbon decomposition rates with depth and contribution of inorganic carbon to {CO}2 emissions under a {M}editerranean agroforestry system},
  author = {{C}ardinael, {R}. and {C}hevallier, {T}iphaine and {G}uenet, {B}. and {G}irardin, {C}. and {C}ozzi, {T}. and {P}outeau, {V}. and {C}henu, {C}.},
  editor = {},
  language = {{ENG}},
  abstract = {{A}groforestry systems have been much studied for their potential to store soil organic carbon ({SOC}). {H}owever, few data are available on their specific impact on potential {SOC} mineralization, especially at depth in subsoils. {M}oreover, many soils of the world, especially in arid and semiarid environments, also contain large stocks of soil inorganic carbon ({SIC}) as carbonates. {C}onsequently, the organic carbon dynamics have been poorly investigated in these soils due to the complexity of measurements and of the processes involved. {T}o assess mineralization rates of {SOC} with depth, we incubated soil samples from an 18-year-old agroforestry system (both tree row and alley) and an adjacent agricultural plot established on a calcareous soil in {F}rance. {S}oil samples were taken at four different depths: 0-10, 10-30, 70-100 and 160-180 cm. {T}otal {CO}2 emissions, the isotopic composition (delta {C}-13, %) of the {CO}2 and microbial biomass were measured. {T}he {SIC} concentrations ranged from 48 to 63 g {C} kg(-1) soil and the {SOC} concentrations ranged from 4 to 17 g {C} kg(-1) soil. {T}he contribution of {SIC}-derived {CO}2 represented about 20% in the topsoil and 60% in the subsoil of the total soil {CO}2 emissions. {T}he microbial biomass and the {SOC}-derived {CO}2 emissions were larger in the topsoil, but the decomposition rates (day(-1)) remained stable with depth, suggesting that only the size of the labile carbon pool was modified with depth. {S}ubsoil organic carbon seems to be as prone to decomposition as surface organic carbon. {N}o difference in {CO}2 emissions was found between the agroforestry and the control plot, except in the tree row at 0-10 cm. {O}ur results suggest that the measurement of soil respiration in calcareous soils could be overestimated if the isotopic signature of the {CO}2 is not taken into account. {I}t also advocates more in-depth studies on carbonate dissolution-precipitation processes and their impact on {CO}2 emissions.},
  keywords = {{C}-13 natural abundance ; carbonates ; deep soil ; {M}editerranean ; metabolic quotient ; microbial biomass ; soil respiration ; {FRANCE} ; {ZONE} {MEDITERRANEENNE}},
  booktitle = {},
  journal = {{E}uropean {J}ournal of {S}oil {S}cience},
  volume = {71},
  numero = {5},
  pages = {909--923},
  ISSN = {1351-0754},
  year = {2020},
  DOI = {10.1111/ejss.12908},
  URL = {https://www.documentation.ird.fr/hor/fdi:010077428},
}