Soil Carbon Sequestration Potential of Climate-Smart Villages in East African Countries

Abstract

Climate-Smart Villages (CSVs) were established by the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS) in the East African countries of Kenya, Tanzania and Uganda to test and promote a portfolio of climate-smart agriculture (CSA) practices that have climate change mitigation potential. This study evaluated the soil carbon sequestration potential of these CSVs compared to the control land use that did not have CSA practices. At the one-meter depth, soil carbon stocks increased by 20–70%, 70–86%, and 51–110% in Kenya, Tanzania and Uganda CSVs, respectively, compared to control. Consequently, CSVs contributed to the reduction of emissions by 87–420 Mg CO2 eq ha−1. In the topsoil (0–15 cm), CSVs sequestered almost twice more soil carbon than the control and subsequently emissions were reduced by 42–158 Mg CO2 eq ha−1 under CSVs. The annual increase in carbon sequestration under CSVs ranged between 1.6 and 6.2 Mg C ha−1 yr−1 and substantially varied between the CSA land use types. The forests sequestered the highest soil carbon (5–6 Mg C ha−1 yr−1), followed by grasslands and croplands. The forest topsoil also had lower bulk density compared to the control. The findings suggest that CSA practices implemented through the CSVs approach contribute to climate change mitigation through soil carbon sequestration.

The Effect of Climate-Smart Agriculture on Soil Fertility, Crop Yield, and Soil Carbon in Southern Ethiopia

“…SOC stock was increased by 100-267 Mg C ha −1 under land uses improved through CSA interventions compared with the control lands where no CSA interventions had been implemented. Previously, Ambaw et al [9] evaluated the contribution of CSA portfolio to soil carbon sequestration under different Eastern African countries and found out that CSA stored 50-95 Mg C ha −1 more SOC than the control, which is comparable with this study. The slightly higher carbon sequestration in this study than the one reported by Ambaw et al [9] could be explained by the following: (i) the farming systems are more intensive in this study than those identified by Ambaw et al [9], and (ii) the CSA interventions have been practiced for a decade in the present study.…”

“…Previously, Ambaw et al [9] evaluated the contribution of CSA portfolio to soil carbon sequestration under different Eastern African countries and found out that CSA stored 50-95 Mg C ha −1 more SOC than the control, which is comparable with this study. The slightly higher carbon sequestration in this study than the one reported by Ambaw et al [9] could be explained by the following: (i) the farming systems are more intensive in this study than those identified by Ambaw et al [9], and (ii) the CSA interventions have been practiced for a decade in the present study. Higher SOC stock under CSA is mainly attributed to carbon input through a combination of different practices, including crop residue incorporation [40], farmyard manure application [41], minimum tillage [42], and restricted-grazing which prevents residue removal [43].…”

“…Climate-smart agriculture (CSA) has been promoted as a prominent strategy to increase crop production in a changing climate, ensure farmers' resilience to climate change, and reduce greenhouse gas emissions [9][10][11]. Subsequently, several CSA practices have been identified, and their significance towards addressing food security challenges and mitigating climate change is very well documented [10,11].…”

“…On this premise, the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS) implemented integrated CSA practices in highly degraded landscapes across different developing countries, including Lushoto (Tanzania), Wote and Nyando (Kenya), Hoima and Rakai (Uganda) [5], and Doyogena (Ethiopia). The integrated CSA practices in these regions include soil and water conservation measures, grazing management, crop rotation, incorporation of crop residues, and perennial-crop based agroforestry systems [5,9]. This study therefore aimed at determining the effect of long-term implementation of integrated CSA interventions on crop yield, soil fertility, and carbon sequestration.…”

Ensemble Modeling on Near-Infrared Spectra as Rapid Tool for Assessment of Soil Health Indicators for Sustainable Food Production Systems

“…A significantly high concentration of exchangeable Ca (18.21 ± 7.51 cmol/kg soil) for surface soils (0-15 cm) under agroforestry land use as compared to the control was probably due to decomposing litter that change the relative quantities of exchangeable base (Ca, Mg) and acid (Al, Fe) cations in soil [45]. Agroforestry through practices such as litter incorporation and manure application has been suggested to improve soil carbon sequestration [48].…”