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

Maren Radeny,John W. Recha,Abebe Nigussie,Dawit Solomon,Gebermedihin Ambaw

doi:10.3390/cli8110124

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.

Highlights

Climate change has contributed to reduced agricultural productivity and threatens food security across the world [1]
This study provides evidence that land restoration through a portfolio of climate-smart agriculture (CSA) practices has the potential to enhance climate change mitigation of highly degraded tropical soils
The annual increase in soil carbon sequestration due to CSA practices ranged between 1.63 and 6.2 Mg C ha−1 yr−1 and varied between the improved land uses across different geographic locations

Summary

Introduction

Climate change has contributed to reduced agricultural productivity and threatens food security across the world [1]. Climate models have predicted more frequent and prolonged extreme weather events such as droughts and floods. These models consider precipitation data available, and accurate attribution of the causes of drought requires accounting for natural variability, especially. Climate change has likely hampered food production in East African countries because the agricultural systems are mainly rainfed and characterized by low inputs such as fertilizers, crop protection chemicals (herbicides, insecticides, and fungicides) and improved seeds [3,4]. In addition to climate-related production constraints, soil nutrient depletion is a challenge to food security in the region [5]. Progressive climate-smart soil management interventions are needed to enhance agricultural production and ensure food security

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Conclusion