Economic Valuation of Soil Erosion on Cultivated Drylands in Langge Sub-watershed, Gorontalo, Indonesia

Abstract

Soil erosion is processes of destruction of soil particles that oftenly suggest large external impacts. Many cases of topsoil losses are caused by the intense rainfall and soil material transport by surface run-off. These events have various negative impacts on agriculture and forestry. This study aims to analyze economic value of soil erosion on cultivated drylands in the Langge sub-watershed, Bolango Watershed,  Gorontalo province, Indonesia. Total economic value of natural resources is the amount of use value and non-use value, use value consists of direct use values and indirect use values. In this study, calculation of economic value is focused on indirect use value, related to the soil fertility losses. Calculation of economic values is based on the cost-based method by estimating any replacement cost. Therefore, estimation of the loss value caused by soil erosion is based on value of organic fertilizers, Urea, SP-36 and KCl. The soil loss in four land units is 406.3 t/ha/season, in which the total rainfall was 855.5 mm/season, total nutrients lost are 2,648.15 kg C/ha/season, 230.26 kg N/ha/ season, 30.47 kg P/ha/season, and 69.74 kg N/ha/season, respectively. Total economic value of the nutrient loss is 14,231,904 IDR/ha/season.

Keyword : Soil erosion, nutrient losses, economic value.