Effects of forest conversion to oil palm plantation on soil erosion and surface runoff

Abstract

The vegetation type and its coverage in forest ecosystems are crucial in soil erosion and surface runoff. Cover crops provide significant protection to the soil aggregates, preventing damage caused by rainfall and runoff that might occur in the absence of these crops. However, changes in land use, such as converting forests into oil palm plantations, have resulted in changes to the land cover, which affect erosion, surface runoff, and, ultimately, the forest ecology of the watershed. This study aimed to provide an overview of erosion and runoff in forest areas and oil palm plantations. This field research was conducted to study erosion, runoff, and nutrient loss using plots measuring 15m x 25m, including oil palm plantation areas and forest areas. After each rain, sediment weighing and runoff volume measurements were carried out. Laboratory analysis was conducted for sediment and surface runoff water samples’ N, P, and K elements. The study results showed that five-year-old oil palm plantation areas experience the highest levels of erosion and runoff, followed by three-year-old oil palm plantation and forest areas. Nutrients were found to be lost in sediment across all land cover types, with a minimal amount recorded in surface runoff.