@inproceedings{fdi:010085502,
  title = {{D}oes agricultural practices impact the quantity and the forms of organic carbon stored in cultivated soils of the {S}enegal groundnut basin ? : a rock-eval approach [r{\'e}sum{\'e}]},
  author = {{M}alou, {O}.{P}. and {S}ebag, {D}. and {M}oulin, {P}atricia and {C}hevallier, {T}iphaine and {N}dour, {Y}.{B}. and {T}hiam, {A}. and {C}hapuis {L}ardy, {L}ydie},
  editor = {},
  language = {{ENG}},
  abstract = {{S}oil organic carbon ({SOC}) is a key element in the functioning of agrosystems. {I}t ensures soil quality and productivity of cultivated systems in the {S}ahelian region. {T}his study uses {R}ock-{E}val pyrolysis to examine how cultural practices impact {SOC} quantity and quality of cultivated sandy soils in the {S}enegal groundnut basin. {S}uch thermal analysis method provides cost-effective information on {SOC} thermal stability that has been shown to be qualitatively related to {SOC} biogeochemical stability. {S}oils were sampled within 2 villages agricultural plots representative of local agricultural systems and for local preserved areas. {T}otal {SOC} concentrations ranged from 1.8 to 18.5 g.kg-1 soil (mean ± standard deviation: 5.6 ± 0.4 g.kg-1 soil) in the surface layer (0-10 cm) and from 1.5 to 11.3 g.kg-1 soil (mean ± standard deviation: 3.3 ± 0.2 g.kg-1 soil) in 10-30 cm deep layer. {SOC} of cultivated soils significantly (p-value < 0.0001) decreased according to treatments in the following order: +organic wastes > +manure > +millet residues > no input. {O}ur results show that the quantity and the quality of {SOC} are linked to each other and both depend on land-use and agricultural practices, especially the nature of organic inputs. {T}his correlation is very strong in the tree plantation ({R}² = 0.98) and in the protected shrubby savanna ({R}² = 0.97). {I}t remains important for cultivated soils receiving organic wastes ({R}² = 0.82), manure ({R}² > 0.75), or millet residues ({R}2 = 0.91) but it's no more significant in no-input situations. {T}he {R}ock-{E}val based indexes were depicted in a {I}/{R} diagram that illustrate the level of {SOC} stabilization and plotted against comparable results from literature. {T}he {S}enegalese sandy soils have thermal signatures showing an inversion of the {I} and the {R} indexes compared to data from the literature and highlighting {SOC} stabilization as a function of soil depth. {I}ndeed, the studied soils were characterized by a more abundant refractory pool ({A}5 which ranged from 7.7 to 21.3 % in 0-10 cm layer and from 12.5 to 24.3 % in 10-30 cm, respectively) compared to other tropical soils. {T}he {SOC} in these sandy soils while positively affected by organic inputs is dominated by labile forms that mineralize quickly which is excellent for the needs of productivity of these agrosystems but not for mitigation of climate change.},
  keywords = {{SENEGAL}},
  numero = {},
  pages = {{EGU}2020--11229 [2 ]},
  booktitle = {},
  year = {2020},
  DOI = {10.5194/egusphere-egu2020-11229},
  URL = {https://www.documentation.ird.fr/hor/fdi:010085502},
}