Location: Watershed Physical Processes ResearchTitle: How irrigation affects soil erosion estimates of RUSLE2
|YODER, DANIEL - University Of Tennessee|
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 9/4/2015
Publication Date: 9/27/2015
Citation: Dabney, S.M., Yoder, D. 2015. How irrigation affects soil erosion estimates of RUSLE2. In Proceedings 3rd Inter-Regional Conference on Land and Water Challenges: Tools for Developing. Sept. 27-30, 2015, Colonia, Uruguay. Agrociencia Setiembre 2015:12-17.
Interpretive Summary: Since 2000, there has been a large increase in soybean production and irrigation in Uruguay. Concern has been expressed that the wetter soil conditions under irrigation could increase the risk of soil erosion by rainfall. The purpose of this study was apply the Revised Universal Soil Loss Equation (RUSLE2) model to Uruguayan conditions to estimate the impact of irrigation on the risk of soil erosion by water. We demonstrated how input climate, soil and management descriptions might be built using available data from Uruguay. Application of RUSLE2 indicated that the susceptibility of soil to erosion is nearly doubled during the irrigation season. However, higher crop yields with irrigation offset this risk because of increased canopy and crop residue cover. For the Uruguayan conditions studied, these two influences largely offset so RUSLE2 predicts only minor impacts of irrigation on water erosion risk. Management with no-till and cover crops was needed to keep estimated soil erosion from soybean cropland below tolerable levels.
Technical Abstract: RUSLE2 is a robust and computationally efficient conservation planning tool that estimates soil, climate, and land management effects on sheet and rill erosion and sediment delivery from hillslopes, and also estimates the size distribution and clay enrichment of sediment delivered to the channel system. In the U.S.A., RUSLE2 is supported by extensive databases maintained by the USDA-Natural Resources Conservation Service. Examples are presented of how input climate, soil and management descriptions might be built outside the U.S.A. using data from Uruguay. In addition to average annual erosion and sediment delivery, recent enhancements give RUSLE2 the ability to predict a representative runoff event sequence for a particular location, soil, management, and user-specified return period that can be coupled with a channel erosion and routing model.