LAUSR

Agroforestry practices offer high potential of carbon (C) sequestration in developing countries. However, the roles of tropical agroforestry to mitigate climate change has only recently been recognized. Therefore, this case study was conducted to demonstrate empirically the carbon stocks of home garden (HGAF) and adjacent coffee based agroforestry systems (CAFS) practiced at Mana district, southwestern Ethiopia. The two agroforestry systems were the predominant natural resources management practices in the study area. A total of 60 nested plots (20 m × 20 m) were established in the two agroforestry systems for inventory of woody species. Three 1 m × 1 m subplots were established in the main plots to collect litter and soil samples. A total of 240 soil samples, 120 for analysis of soil organic carbon fraction (%C), and 120 for bulk density determination, were collected. We estimated the total C stock by summing C stock in the biomass and soil (0–60 cm depth). Results showed that, the total biomass C stocks (above and belowground) significantly differed between HGAF (27.4 ± 16.9 Mg C ha −1 ) and adjacent CAFS (63.1 ± 31.5 Mg C ha −1 ) ( p  < 0.05). Trees accounted for 67% and 85% of the total biomass C stocks in HGAF and CAFS, respectively. Litter constituted 3% of the total aboveground biomass carbon stock in the HGAF and 6% in the CAFS. The total C stocks (in biomass plus soil, 0–60 cm depth) were significantly higher in the CAFS (194.96 ± 34.65 Mg C ha −1 ) compared to HGAF (157.77 ± 29.20 Mg C ha −1 ). The soil organic carbon accounted for 82% for HGAF and 68% for CAFS’s total C stocks. Our study revealed that the agroforestry systems can be C sinks in agricultural landscapes and support local livelihoods.