Building Climate Change Adaptation and Resilience through Soil Organic Carbon Restoration in Sub-Saharan Rural Communities: Challenges and Opportunities

Abstract

Soil organic carbon (SOC) is widely recognised as pivotal in soil function, exerting important controls on soil structure, moisture retention, nutrient cycling and biodiversity, which in turn underpins a range of provisioning, supporting and regulatory ecosystem services. SOC stocks in sub-Saharan Africa (SSA) are threatened by changes in land practice and climatic factors, which destabilises the soil system and resilience to continued climate change. Here, we provide a review of the role of SOC in overall soil health and the challenges and opportunities associated with maintaining and building SOC stocks in SSA. As an exemplar national case, we focus on Tanzania where we provide context under research for the “Jali Ardhi” (Care for the Land) Project. The review details (i) the role of SOC in soil systems; (ii) sustainable land management (SLM) techniques for maintaining and building SOC; (iii) barriers (environmental, economic and social) to SLM implementation; and (iv) opportunities for overcoming barriers to SLM adoption. We provide evidence for the importance of site-specific characterisation of the biophysicochemical and socio-economic context for effective climate adaptation. In particular, we highlight the importance of SOC pools for soil function and the need for practitioners to consider the type of biomass returns to the soil to achieve healthy, balanced systems. In line with the need for local-scale site characterisation we discuss the use of established survey protocols alongside opportunities to complement these with recent technologies, such as rapid in situ scanning tools and aerial surveys. We discuss how these tools can be used to improve soil health assessments and develop critical understanding of landscape connectivity and the management of shared resources under co-design strategies.

Soils, Science and Community ActioN (SoilSCAN): a citizen science tool to empower community-led land management change in East Africa

“…As such, building and maintaining healthy SOC pools is acknowledged in the UNCCD as essential for underpinning soil ecosystem services and achieving global Sustainable Development Goals (SDGs) (FAO 2017). Given that SOC can be impacted by land use, and the importance of site specific factors upon SOC formation and storage (Swanepoel et al 2018), our study shows that targeted measurements of SOC can be used to inform local-scale land use planning and complement wider measurements of soil health such as aggregate stability and infiltration capacity (Taylor et al 2021). At the international level, the project delivers into the UN Food and Agricultural Organisation (FAO) World Soils Charter 'to manage land for long-term advantage rather than for short-term expediency' (FAO 2015).…”

“…Soil organic carbon (SOC) is of fundamental importance to soil health, exerting important controls on soil functions including moisture retention, aggregate formation and nutrient cycling (Lefèvre et al 2018, Stewart et al 2020, Taylor et al 2021. SOC is, therefore, widely accepted as a key indicator of soil health (Liniger et al 2011).…”

“…When properly designed, carried out, and evaluated, citizen science can provide sound science, efficiently generate highquality data, and help solve problems' (Mckinley et al 2017, p 15). Our ongoing participatory soil erosion research in northern Tanzania (Kelly et al 2020, Taylor et al 2021 has highlighted an urgent need for accessible technology to assess soil health parameters, to enable communities to design long-term soil erosion repair and rehabilitation plans, alongside sustainably increasing crop yields to maintain precarious livelihoods. Use of a hand-held soil scanner provides a key opportunity to work with one Tanzanian community to test the applicability and utility of the technology in a process of 'collaborative citizen science' , as defined by Pocock et al (2018).…”

European agricultural soil management: Towards climate‐smart and sustainability, knowledge needs and research approaches

“…Agroecology needs to find suitable weed control measures, solve fertilization issues, and use soil biodiversity and other nature-based solutions as alternatives to agro-chemicals (Fenster et al, 2021). A higher organic matter content in the soil can increase soil's water holding capacity that will reduce the need for irrigation (Taylor et al, 2021). These plot scale solutions need to be embedded in the landscape approach.…”

Removal of Toxic Metals from Sewage Sludge by Edta in a Closed-Loop Washing Process

“…Although C, N, and K sources are not at risk of depletion and for this reason are not considered as strategic as P, they are still critical to soil ecosystem services. For example, the decline and loss of soil C due to intensive agriculture reduces soil fertility and resilience (Taylor et al, 2021) and contributes to global CO 2 emissions. Similarly, fertilization of agricultural soils with mineral N produced by the Haber-Bosch process (which is one of the largest greenhouse gas emitters) is responsible for 1.2% of global anthropogenic CO 2 emissions (Smith et al, 2020).…”