Estimation of Soil Loss Ratio (SLR) for Horticultural Crops in Southern Uruguay

Abstract

Most of the horticultural production systems in southern Uruguay are unsustainable, mainly because of water erosion proble-ms. The Universal Soil Loss Equation (USLE) is a tool to estimate soil loss. It has been adapted and validated for extensive, forestry and pasture systems in Uruguay, but not for horticultural systems. Through the revised RUSLE version (Renard et al., 1997) the soil loss relations (SLR) for horticultural crops were estimated. Measurements were made in three horticultural systems (livestock- horticultural rotation, horticultural rotation, and conventional horticulture) during 2008 and 2009. The aim of this study was to estimate the SLR for 16 horticultural crops, for conventional and conservationist production systems. SLR values varied depending on the crop, the highest values (maximum 0.5) were found in USLE periods 0, 1 and 4 (for crops where entire plant is harvested or where the furrow is turned), and crops that do not cover the furrow and the interrill. The lower values were associated with short cycle crops, that rapidly cover the furrow and interrill, and where the plant remains after the harvest until the next tillage. SLR values could be employed to estimate the C Factor of different horticultural systems to be used in the EROSION 6.0 program to calculate soil loss by water erosion. This tool facilitates decision-making in the design and evaluation of existing and alternative production systems under conditions of climate change for sustainable management.