Impact of land degradation on agricultural productivity and household and food security: evidence from smallholder farmers in a semi-arid region of South Africa.

Abstract

Land degradation is a global concern with far-reaching implications for both developed and developing nations, particularly in the context of climate change. However, there remains a critical gap in research and policy regarding the relationship between socioeconomics, land quality, and soil health. Existing studies often rely on remote sensing data to raise awareness but are ambiguous to guide sustainable development approaches grounded in socio-economic development. To address this knowledge gap, the study surveyed 256 smallholder farmers using a structured questionnaire developed in line with the Food and Agriculture Organization (FAO) Land Degradation Assessment in Drylands (LADA) framework, complemented by various analytical tools and statistical models. The research aimed to understand the drivers and consequences of land degradation on agricultural productivity and food security in semi-arid regions particularly the Sekhukhune District Municipality. The research went beyond immediate agricultural effects by examining socio-economic impacts and coping strategies of smallholder farmers. The study examined how smallholder farmers choose strategies to adapt to the impacts of land degradation and further explored factors influencing decision making. To understand this, the study utilised an integrated analytical approach that combined descriptive statistics with binary logistic regression, multivariate probit (MVP), multiple linear regression (MLR), propensity score matching (PSM), ordinal logistic regression (OLR), and structural equation modelling (SEM). Agricultural productivity is assessed through an Agricultural Land Productivity Index (ALPI) adapted from the Alkire-Foster counting approach. Food security is measured with the Household Food Insecurity Access Scale (HFIAS) technique. The study began by examining the dominant forms of land degradation prevalent in the Sekhukhune District Municipality and found that they primarily manifest in the form of water erosion (36.8%), soil compaction (28.1%), topsoil loss (26.6%), waterlogging (25.0%), and wind erosion (24.6%), however, a strong co-movement observed among water erosion, topsoil loss, and compaction was observed. Additional forms of degradation identified included invasive species, vegetation degradation, and salinity, which together exacerbate the decline in soil and ecosystem health. These processes are intensified by unsustainable agricultural practices, deforestation, and mining activities, which collectively diminish arable land, deplete essential soil nutrients, and aggravate water scarcity. The study also examined farmers’ coping and adaptation strategies employed to mitigate its adverse effects. The study found that adoption of coping strategies varies greatly in the area, conservation tillage is adopted at (28.4%), crop diversification (19.7%), and use of crop residues (15.8%) lead, while mulching, crop rotation, organic manure, and fertiliser use remain marginal. Results from the logistic regression model indicate that household size (p < 0.01), education (p < 0.05), and participation in landcare projects (p < 0.10) significantly enhance the likelihood of adopting coping strategies. The multivariate probit (MVP) model confirms the existence of complementarities among strategies such as conservation tillage combined with residue retention and crop diversification suggesting that farmers employ integrated rather than isolated responses. Regarding exposure to degradation, the Probit model highlights the significant roles of age, gender, land ownership, access to information, and adoption of sustainable land management (SLM) (model R² = 0.27). Older, male-headed, and tenure-secure households are less likely to experience degradation, while SLM adoption significantly reduces exposure. Interestingly, the positive coefficient on access to information implies persistent quality gaps in extension delivery and knowledge dissemination. Additionally, the study evaluated the impacts of land degradation on agricultural productivity and household food security. Results from the Propensity Score Matching (PSM) model estimate an Average Treatment Effect on the Treated (ATT) of -0.824, implying an average 82.4% reduction in agricultural productivity among affected households. Land degradation further worsens welfare outcomes, as households experiencing degradation are 25.5% more likely to be food insecure (p = 0.053). Findings from the Ordinal Logistic Regression (OLR) model identify land degradation, low income, limited education, and insecure land rights as significant predictors of heightened food insecurity. Conversely, the adoption of sustainable land management (SLM) practices exhibits a strong protective effect, mitigating the negative impacts of degradation on both productivity and food access. The Structural Equation Model (SEM) clarifies the underlying mechanisms: land degradation indirectly increases food insecurity through its negative impact on agricultural productivity, while a modest positive direct pathway suggests that social grants and relief interventions may temporarily buffer households against acute food shortages, though they fail to address the structural risks driving vulnerability. These results indicate the need for increased awareness among smallholder farmers regarding the impacts of land degradation and the importance of adopting sustainable land management practices. These findings are also of importance for policy development and implementation. In South Africa, communal and grazing areas face significant land degradation challenges driven by historical land systems, mining, climate change, overgrazing, and unsustainable practices, compounded by erosion and deforestation. A wide-ranging approach is recommended, including sustainable farming practices, equitable resource access, education, land distribution, reforestation, and improved land management. The study recommends holistic, informed policy interventions addressing the root causes of land degradation, promoting sustainable land management, improving rural education and resource access, and enhancing adaptation to environmental changes. Policymakers should encourage the adoption of Sustainable Land Management technologies, particularly among non-adopters, focusing on gender and youth integration. Capacity-building programs, advocacy, and enhanced extension staff skills are crucial elements. Additionally, government support for extension services and technology dissemination can influence adoption decisions, ultimately enhancing resilience and food security in the face of land degradation challenges. This research further critiqued the existing literature for neglecting ecological mechanisms, climate change interactions, and socio-economic factors contributing to land degradation, particularly in developing countries. Recognizing land degradation's severe impacts, global initiatives like the United Nations Convention to Combat Desertification and Sustainable Development Goals aim to combat it. Furthermore, the study identifies areas for further research, such as long-term impact assessment, climate change resilience strategies, economic valuation, gender and youth inclusion, policy implementation, community-based initiatives, capacity-building, and interdisciplinary approaches, to comprehensively address the complex challenges of land degradation and food security.