Balancing Carbon Sequestration, Soil Retention, and Crop Yield: A Systematic Review of Sustainable Land Management Practices in Sub-Saharan Africa

Land degradation and soil fertility decline remain among the most persistent constraints on agricultural productivity and ecosystem sustainability in sub-Saharan Africa (SSA). It is estimated that more than 65% of agricultural land in SSA is affected by varying degrees of degradation, primarily driven by continuous cultivation, nutrient mining, erosion and climate variability (Zingore et al., 2015). Central to this degradation is the depletion of soil organic carbon (SOC), a key indicator of soil health that underpins nutrient cycling, soil structure, water retention, and biological activity (Song et al., 2023). In response, Sustainable Land Management (SLM) has emerged as a guiding paradigm for reversing land degradation while maintaining agricultural productivity. According to the (Nekesa et al., 2024) SLM refers to the use of land resources, soil, water, biodiversity, and vegetation through practices that maximise economic and social benefits while maintaining or enhancing ecological functions. In SSA, SLM practices such as conservation agriculture, agroforestry, integrated soil fertility management, and soil and water conservation structures are widely promoted as pathways to restore SOC stocks and improve land resilience(Vågen et al., 2005) . Soil carbon sequestration is frequently considered a central biophysical outcome of SLM. Increasing SOC stocks through improved land management has been proposed as a “win–win” strategy capable of enhancing crop productivity, increasing resilience to climate variability, and mitigating climate change through atmospheric CO₂ removal (Moinet et al., 2023). This narrative has gained further prominence under the framework of Climate-Smart Agriculture (CSA), which explicitly seeks to achieve three simultaneous objectives: (i) sustainably increase agricultural productivity, (ii) strengthen adaptation and resilience to climate change, and (iii) reduce or remove greenhouse gas emissions, where possible (Begna & Begna, 2025). However, growing empirical evidence challenges the assumption that soil carbon sequestration under SLM is universally synergistic across these three CSA pillars. In SSA, agricultural systems are predominantly smallholder-based, resource-constrained, and closely integrated with livestock production. Consequently, practices that promote SOC accumulation often involve trade-offs, particularly related to biomass allocation, labour demands, nutrient availability, and greenhouse gas dynamics(Spotorno et al., 2025). One of the most documented trade-offs is the use of crop residues. While residue retention is critical for SOC buildup and erosion control, residues also serve as essential livestock feed and household energy sources in mixed crop–livestock systems that are common across SSA (Tittonell et al., 2015). Empirical studies have demonstrated that the residue retention thresholds required to significantly increase SOC are rarely met under smallholder conditions, thereby limiting the mitigation potential of conservation agriculture in practice (Giller et al., 2015). Beyond productivity constraints, SOC sequestration plays a nuanced role in climate adaptation. Enhanced SOC improves soil water holding capacity and aggregate stability, which can buffer crops against rainfall variability and drought stress (Lal 2016). Nevertheless, many SLM practices that increase SOC, such as stone bunds, zaï pits, and agroforestry establishment, are labour-intensive and require delayed returns on investment, creating barriers to adoption under conditions of climate and economic uncertainty (Zougmoré et al., 2014). Consequently, farmers often prioritise short-term risk reduction over long-term carbon storage, positioning SOC sequestration as a co-benefit rather than as a primary objective. From a mitigation perspective, the climate benefits of SOC sequestration under SLM are further complicated by its interactions with non-CO₂ greenhouse gases. Increased organic inputs and nitrogen availability can stimulate nitrous oxide (N₂O) emissions, potentially offsetting the gains from carbon sequestration, particularly in tropical soils with high emission factors (Pelster et al., 2017; Mapanda et al., 2011). Moreover, many soils in SSA are characterised by low clay content and limited carbon stabilisation capacity, raising concerns regarding carbon saturation and the long-term permanence of sequestered SOC (Zingore et al., 2015). Despite these complexities, most existing studies in SSA assess SOC sequestration in isolation without explicitly quantifying trade-offs across productivity, adaptation, and mitigation objectives. Systematic analyses integrating the biophysical, socioeconomic, and spatial dimensions of SLM-induced SOC changes remain scarce. This gap limits policymakers and development programs’ ability to design SLM interventions that are both climate-effective and locally viable. Against this backdrop, a systematic synthesis of the literature on SLM and soil carbon sequestration trade-offs in SSA, explicitly framed through CSA pillars, is urgently needed. Such an analysis is critical to move beyond simplified “triple-win” narratives toward evidence-based strategies that recognise context-specific constraints, synergies, and limits. Understanding where, when, and under what conditions SLM contributes positively, or negatively, to productivity, adaptation, and mitigation is essential for aligning soil carbon strategies with sustainable development and climate resilience goals in Sub-Saharan Africa