41
© Springer Nature Switzerland AG 2020
B. R. Singh et al. (eds.), Climate Impacts on Agricultural and Natural Resource
Sustainability in Africa, https://doi.org/10.1007/978-3-030-37537-9_3
Land Use Changes and Sustainable Land
Management Practices for Soil Carbon
Sequestration in Sub-Saharan African
Agro-ecosystems
Kennedy Were, Bal Ram Singh, and George Ayaga
Abstract Land use plays an important role in the global system. It alters in response
to changing human needs driven by an array of socio-economic, technological,
political, and environmental factors. However, the rate of land use change in subSaharan Africa (SSA) remains alarming due to a population that is rapidly growing
at the rate of 2.6% annually and technological advances leading to the transformation of the land surface. For example, between 2010 and 2015, the rate of forest
decline was about 2.8 million ha year
−1
. The prominent mode of transformation has
been the conversion of fragile native ecosystems (i.e., forests, woodlands, savannahs, grasslands, and steppe) into agro-ecosystems in order to fulfill the escalating
demand for food, fiber, fuel, and shelter. This has had ramifications on the principal
carbon (C) pools, especially the soil organic C (SOC) pool. Studies have shown that
a decline in SOC stocks following deforestation in SSA can at times exceed 50%.
However, the exact magnitude of SOC depletion in SSA is still uncertain owing to
scarcity of reliable long-term data needed for accounting. Replenishing SOC stocks
in SSA agro-ecosystems calls for adoption of a combination of appropriate sustainable land management (SLM) practices (e.g., conservation agriculture (CA) and
integrated nutrient management), which can enhance the capture and storage of C in
plants and soils, as well as mitigate GHG emissions and climate change. For example, soil C sequestration under CA and fertilizer use in Africa has, on average, been
0.37 Mg C ha
−1
year
−1
and 0.63 Mg C ha
−1
year
−1
, respectively. In this chapter, we
K. Were (*)
Kenya Agricultural and Livestock Research Organisation, Food Crops Research
Centre - Kabete, Nairobi, Kenya
B. R. Singh
Faculty of Environmental Sciences and Natural Resource Management, Norwegian
University of Life Sciences, Ås, Norway
G. Ayaga
Kenya Agricultural and Livestock Research Organization, Food Crops Research
Centre - Alupe, Busia, Kenya
© Springer Nature Switzerland AG 2020
B. R. Singh et al. (eds.), Climate Impacts on Agricultural and Natural Resource
Sustainability in Africa, https://doi.org/10.1007/978-3-030-37537-9_3
Land Use Changes and Sustainable Land
Management Practices for Soil Carbon
Sequestration in Sub-Saharan African
Agro-ecosystems
Kennedy Were, Bal Ram Singh, and George Ayaga
Abstract Land use plays an important role in the global system. It alters in response
to changing human needs driven by an array of socio-economic, technological,
political, and environmental factors. However, the rate of land use change in subSaharan Africa (SSA) remains alarming due to a population that is rapidly growing
at the rate of 2.6% annually and technological advances leading to the transformation of the land surface. For example, between 2010 and 2015, the rate of forest
decline was about 2.8 million ha year
−1
. The prominent mode of transformation has
been the conversion of fragile native ecosystems (i.e., forests, woodlands, savannahs, grasslands, and steppe) into agro-ecosystems in order to fulfill the escalating
demand for food, fiber, fuel, and shelter. This has had ramifications on the principal
carbon (C) pools, especially the soil organic C (SOC) pool. Studies have shown that
a decline in SOC stocks following deforestation in SSA can at times exceed 50%.
However, the exact magnitude of SOC depletion in SSA is still uncertain owing to
scarcity of reliable long-term data needed for accounting. Replenishing SOC stocks
in SSA agro-ecosystems calls for adoption of a combination of appropriate sustainable land management (SLM) practices (e.g., conservation agriculture (CA) and
integrated nutrient management), which can enhance the capture and storage of C in
plants and soils, as well as mitigate GHG emissions and climate change. For example, soil C sequestration under CA and fertilizer use in Africa has, on average, been
0.37 Mg C ha
−1
year
−1
and 0.63 Mg C ha
−1
year
−1
, respectively. In this chapter, we
K. Were (*)
Kenya Agricultural and Livestock Research Organisation, Food Crops Research
Centre - Kabete, Nairobi, Kenya
B. R. Singh
Faculty of Environmental Sciences and Natural Resource Management, Norwegian
University of Life Sciences, Ås, Norway
G. Ayaga
Kenya Agricultural and Livestock Research Organization, Food Crops Research
Centre - Alupe, Busia, Kenya