Analysis of the effect of terracing on soil erosion control. A case study of Mutete sector, Gicumbi District, Rwanda

Abstract

Land degradation poses a significant threat to agricultural and environmental development in the twenty-first century. Soil erosion, one of the major concerns, adversely affects agriculture, wildlife, and water bodies. It can be mitigated by maintaining protective soil cover or altering landscapes to manage runoff. In Gicumbi district's Mutete zone, northern Rwanda, terraces have been implemented as a key strategy for combating soil erosion, conserving water, and enhancing agricultural productivity—an approach that has been in practice for thousands of years. Despite its long history, the full range of terracing's effects and underlying mechanisms remains poorly understood due to challenges such as large-scale implementation, spatial variability, and difficulties in measuring its impact on soil erosion control. This study aims to examine the availability of land for agricultural practices on terraced versus non-terraced land, assess the impact of terracing on agricultural land use, and understand farmers' perceptions of its benefits and challenges. The study also evaluates soil erosion rates on both terraced and non-terraced lands through field observations. Using a combination of literature review, site visits, questionnaires, and interviews, the effects of terracing on soil erosion control were analyzed in terms of performance, suitability, cost-effectiveness, labor intensity, and long-term sustainability. The study found that terraced lands experience significantly lower soil erosion compared to nonterraced areas, but around 20% of arable land is lost to terrace structures. Farmers view this land loss and the labor-intensive nature of terracing as barriers to adoption. However, government subsidies, particularly in land consolidation programs, have made terracing more accessible. Despite the initial costs and labor demands, the long-term benefits, such as improved soil retention and higher crop yields, make terracing a worthwhile trade-off for farmers. Challenges related to labor and maintenance exist, but are outweighed by improved agricultural output. Farmers also called for more training, technical support, and expanded fertilizer programs to maximize terracing’s benefits. While terracing has clear advantages, its negative impacts are often overlooked, and current studies have gaps in understanding its full effects. In conclusion, the adoption of terracing technology is influenced by a variety of factors, both promoting and hindering its effectiveness. Policymakers and planners should address these constraints when designing, implementing, and maintaining terracing as a critical soil erosion control measure. .