@article{fdi:010089871,
  title = {{D}ynamics of soil organic carbon pools following conversion of savannah to cocoa agroforestry systems in the {C}entre region of {C}ameroon},
  author = {{F}onkeng, {E}.{E}. and {C}hevallier, {T}iphaine and {S}auvadet, {M}. and {E}nock, {S}. and {R}akotondrazafy, {N}. and {C}hapuis-{L}ardy, {L}ydie and {T}akoutsing, {B}. and {T}abi {F}ritz, {O}. and {H}armand, {J}.{M}.},
  editor = {},
  language = {{ENG}},
  abstract = {{A}fforestation of gramineous-woody savannah with cocoa agroforestry systems (c{AFS}) is a common farmer practice in {C}ameroon considered as sustainable. {N}evertheless, the effects of afforestation of savannah with c{AFS} on soil organic carbon ({SOC}) turnover and content, and the factors controlling {SOC} accumulation and stabilization are unknown. {SOC} content at 0-10 cm soil layer, and {SOC} distribution in soil particle size fractions (0-20 {M}u m fraction considered as mineral-associated organic carbon, {MAOC}; 50-2000 {M}u m considered as particulate organic carbon, {POC}; and 20-50 {M}u m), were compared in different systems settled on degraded savannah (orthic ferralsols). {T}hese systems included annual cropland (average 5 years old), cocoa monoculture (average 10 years old), and c{AFS} (from 20 to 60 years old) including different shade tree species such as {A}lbizia adianthifolia, {C}anarium schweinfurthii, {D}acryodes edulis, {M}ilicia excelsa and {C}eiba pentandra. {S}avannah and nearby secondary forest patches were also included in the design as controls. {S}oil 13{C} was analysed to investigate the soil carbon turnover after afforestation ({C}3 plants) of gramineous savannah ({C}4 plants). {SOC} significantly increased in the 0-10 cm depth from 10.6 ± 3.1 g {C} kg-1 in degraded savannah to 17.9 ± 5.6 g {C} kg-1 in c{AFS} reaching similar levels as in nearby secondary forests (16.3 ± 5.8 g {C} kg-1), while annual cropland and cocoa monoculture presented a non-significant decrease in {SOC} content. {T}hese changes were due to rapid loss of {SOC} derived from savannah plants ({C}4) - about 76% within the first 15 years after conversion, and higher gain of {SOC} derived from {C}3 plants in c{AFS} than in the other land uses (e.g. from 3.4 ± 1.5 g {C} kg-1 in savannah to 17.8 ± 5.7 g {C} kg-1 in c{AFS}). {T}his {SOC} enrichment in c{AFS} was distributed in {POC} (64%), {MAOC} (30%) and the intermediate 20-50 {M}u m soil fraction (6%). {T}he higher annual litter input accumulated on a longer period in c{AFS} (20 to 60 years) than in cocoa monoculture (10 years) concomitant with the lower litter recalcitrance of associated trees compared to cocoa could explain the higher enrichment of {SOC} in all fractions in c{AFS}. {T}he soil p{H} and exch. {C}a2+ differed under the different shade tree species, and were positively correlated to {SOC} content. {T}he highest contents of soil exch. {C}a2+ induced by {C}eiba and {M}ilicia in the top 10 cm soil layer could contribute to increase {SOC} enrichment under those species through soil aggregation and related {C} stabilization. {W}e found no strong evidence of the effect of soil texture on additional soil carbon accumulation in c{AFS}, especially for the more stable {C} pool ({MAOC}). {O}ur results evidenced that savannah afforestation with c{AFS} appears as a valuable option for top soil carbon enrichment and should consider tree species associated to cocoa to enhance soil {C} sequestration, soil quality and cocoa production sustainability.},
  keywords = {{CAMEROUN} ; {BAKOA} ; {GUEFIGUE}},
  booktitle = {},
  journal = {{G}eoderma {R}egional},
  volume = {36},
  numero = {},
  pages = {e00758 [14 ]},
  ISSN = {2352-0094},
  year = {2024},
  DOI = {10.1016/j.geodrs.2024.e00758},
  URL = {https://www.documentation.ird.fr/hor/fdi:010089871},
}