Intersecting RUSLE modelled and farmers perceived soil erosion risk in the conservation domain on mountain Elgon in Uganda

Abstract

This study investigated the intersection between empirically derived and farmers perceived soil erosion risk in a medium-sized catchment on the Ugandan side of mountain Elgon. We postulated that farmers' perception of soil erosion risk was high and this influenced their employment of Soil and Water Conservation (SWC) measures on their land. An adapted Revised Universal Soil Loss Equation (RUSLE) was employed to model the soil erosion risk in a Geographical Information System (GIS) environment. Participatory Learning and Action (PLA) tools covering household interviews and Focus Group Discussions (FGDs) were implemented in two representative subcounties of the catchment to elicit information on farmers' perception of soil erosion risk. Household interviews covering 184 respondents were georeferenced using a Geographical Positioning System (GPS). Farmers perceived soil erosion risk on their land was then matched with RUSLE modelled risk using GPS positional data. The modelled soil erosion risk was substantial and a sizeable proportion of the catchment (63%) exhibited soil losses >10 t ha-1 yr-1, which is considered above the tolerable limit for mountain environments. A slight but significant agreement (p < 0.001) between the modelled and farmers perceived soil erosion risk was observed. In general, farmers perceived soil erosion risk was less than the RUSLE model estimates. Although 95% of farmers recognize soil erosion as problematic, only 65% implemented some aspect of SWC on their land albeit with varied purposes. Chi-square tests did not detect a strong association (p > 0.05) between farmers' perceived soil erosion risk and implementation of SWC on their land. On this basis, our postulation that perceived high soil erosion risk influences the implementation of SWC does not suffice in the studied catchment. We surmise that successful risk mitigation should be directed more on increasing farmer's awareness of the long-term adverse consequences of soil erosion on their land.