Drivers of soil organic carbon stocks at village scale in a sub-humid region of Zimbabwe
2025
Nyawasha, Rumbidzai W. | Falconnier, Gatien, N | Todoroff, Pierre | Wadoux, Alexandre, M. J.-C. | Chikowo, Regis | Coquereau, Adrien | Leroux, Louise | Jahel, Camille | Corbeels, Marc | Cardinael, Rémi | University of Zimbabwe (UZ) | Agroécologie et intensification durables des cultures annuelles (UPR AIDA) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad) | Département Performances des systèmes de production et de transformation tropicaux (Cirad-PERSYST) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad) | International Maize and Wheat Improvement Center [Zimbabwe] (CIMMYT) ; International Maize and Wheat Improvement Center (CIMMYT) ; Consultative Group on International Agricultural Research [CGIAR] (CGIAR)-Consultative Group on International Agricultural Research [CGIAR] (CGIAR) | Laboratoire d'étude des Interactions Sol - Agrosystème - Hydrosystème (UMR LISAH) ; Institut de Recherche pour le Développement (IRD)-AgroParisTech-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Montpellier ; Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro) | Territoires, Environnement, Télédétection et Information Spatiale (UMR TETIS) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | International Institute of Tropical Agriculture (IITA Kenya) ; International Institute of Tropical Agriculture [Nigeria] (IITA) ; Consultative Group on International Agricultural Research [CGIAR] (CGIAR)-Consultative Group on International Agricultural Research [CGIAR] (CGIAR) | Département Environnements et Sociétés (Cirad-ES) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad) | This study was funded by the DSCATT project “Agricultural Intensification and Dynamics of Soil Carbon Sequestration in Tropical and Temperate Farming Systems” (N◦AF 1802-001, N◦FT C002181), supported by the Agropolis Foundation (“Programme d’Investissement d’Avenir” Labex Agro, ANR-10-LABX- 0001-01) and by the TOTAL Foundation within a patronage agreement. Rumbidzai W. Nyawasha also received additional funding from the RAIZ “Promoting agroecological intensification for resilience building” project FOOD/2021/424- 933 (https://raiz.org.zw/) funded by the European Union | ANR-10-LABX-0001,AGRO,Agricultural Sciences for sustainable Development(2010)
International audience
显示更多 [+] 显示较少 [-]英语. Land use change caused by agriculture and inappropriate agricultural management cause soil organic carbon (SOC) loss. This study was conducted in a smallholder communal area of Zimbabwe with the following objectives: i) to quantify SOC stocks under contrasting land uses and soil types, and estimate landscape-level SOC stocks, ii) to assess the impact of historical agricultural management parctices on SOC in croplands (homefields vs outfields), and iii) to estimate temporal changes in SOC stocks due to land use change using field measurements and geospatial data (Africa Soil Information Service, AfSIS). SOC stocks were measured across three soil types and eight land uses (croplands, gardens, fallows, grasslands, vleis, shrublands, forests and tree plantations) at soil depths of 0-20 and 20-40 cm. Estimates from AfSIS were also used for comparison. SOC stocks were highest on black clay soils (66.9 ± 2.30 Mg C/ha), followed by red clay soils (36.1 ± 2.04 Mg C/ha) and sandy soils (25.5 ± 0.59 Mg C/ha). Among land uses, SOC stocks were highest in vleis (67.9 ± 3.55 Mg C/ha), followed by gardens (56.4 ± 2.34 Mg C/ha) and grasslands (53.1 ± 6.18 Mg C/ha). Croplands on sandy soils had the lowest stocks (22.7 ± 0.77 Mg C/ha). Distance from homestead had no significant effect on SOC stocks. SOC stocks estimated by AfSIS were systematically underestimated in vleis, grasslands and gardens, resulting in a 20 % underestimation of landscape SOC stocks. Landscape SOC stocks declined slightly (-0.2 %) from 2002 to 2023, though the change was not statistically significant. Our findings highlight that SOC stocks hotspots are concentrated in vleis, gardens and grasslands, mostly within communal grazing lands. Their conservation should therefore be a priority, emphasizing the need for collective management. On the other hand, restoration of degraded croplands could be enhanced by strenghtening linkages between cultivated fields and communal grazing lands through improved livestock management.
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