Publisher's Synopsis
Erosion from water runoff is the principal cause of soil degradation in the Peruvian Amazon and worldwide. According to the Millennium Ecosystem Assessment incompatible land uses and poor land management practices continue to increase land degradation. Peru is confronting these practices through agricultural zoning, specifically Ecological Economic Zoning, which includes a Best Use Capacity of Soils diagnostic. However, the implementation of zoning with the Best Use Capacity of Soils has been limited in small-scale agriculture communities. One of the challenges to implement zoning in these communities is the difference in scale between soil use capacity areas and agricultural lots, usually five to twenty hectares, in which farmers make land use decisions. This study tests the possibility of closing the gap between the scale of agricultural zoning and the scale of small farms using the Universal Soil Loss Equation (USLE) applied to a rural watershed using raster maps in GIS. Although the precision of soil loss estimates is limited due to data resolution, our use of USLE reveals differences in soil erosion vulnerability within the Best Use Capacity of Soils mapping units and at a much finer resolution. We find that USLE applied with GIS is an affordable and time efficient tool for interpreting Best Use Capacity of Soils maps at the scale of the small farm. With future development of USLE factors specific to the region, this methodology could have an important policy role for agricultural zoning in small farm communities.
