Location: Watershed Physical Processes Research
Project Number: 6060-13000-029-050-I
Project Type: Interagency Reimbursable Agreement
Start Date: Sep 1, 2025
End Date: Aug 31, 2030
Objective:
This agreement between the U.S. Department of Agriculture, Natural Resources Conservation Service (NRCS), and the U.S. Department of Agriculture, Agricultural Research Service (ARS), aims to continue maintaining the Revised Universal Soil Loss Equation (Version 2) (RUSLE2) for NRCS use and to develop a new RUSLE2 web-based application for conservation planners. RUSLE2, a water erosion prediction tool used by NRCS, is a revision of the previous RUSLE model. Conservation planners utilize the RUSLE2 program to estimate soil loss from sheet and rill erosion under various cropping and management systems. Farmers depend on this information to make decisions about farm management, select conservation practices, and develop plans to manage highly erodible land as required for USDA program eligibility. The RUSLE2 software is currently being updated to enhance erosion estimates and usability, including the development of a web-based tool to facilitate access for agency staff and the public. This will directly benefit producers by providing reliable soil erosion estimations essential for HELC compliance, resource concern assessment, and practice development for USDA programs.
The primary objective is to maintain the Revised Universal Soil Loss Equation (Version 2) for NRCS use. Additional objectives include continuing: 1. maintenance (such as addressing issues related to changing CEC definitions), 2. programming, and 3. debugging of RUSLE2 for NRCS purposes.
The NRCS has been using various versions of the RUSLE2 for many years. RUSLE2 is an essential tool for NRCS and the programming that is needed to integrate into the NRCS Conservation Delivery Streamlining Initiative (CDSI). NRCS is developing the Erosion Tools Suite (ETS) that utilizes corporate data sets for soil, climate, and management. Currently, ETS will not provide all the functionality of the stand-alone RUSLE2, so the stand-alone version of RUSLE2 must be maintained. The data sets that the ETS and stand-alone RULSE2 use may not be synchronized if this is not done by the field office staff. Modifying RUSLE2 to a web-based application to consume Land Operations Management Database (LMOD) and other web-based data will ensure that the planner can get the same answer for a simple situation from both the stand-alone and web-based RUSLE2, and that the stand-alone RUSLE2 will use the same, up-to-date management data in more complicated situations that is available to NRCS planners through ETS.
7 CFR § 610.14 - Use of USLE, RUSLE, and WEQ, specifies the use of the USLE and its replacements (e.g., RUSLE, RUSLE2). The statute legally requires RUSLE to be used to: (1)(i) Evaluate the soil loss estimates of conservation systems contained in the FOTG. (ii) Evaluate the soil loss estimates of systems actually applied, where those systems were applied differently than specified in the conservation plan adopted by the producer or where a conservation plan was not developed, in determining whether a producer has complied with the HEL conservation provisions of the Food Security Act of 1985, as amended, 16 U.S.C. 3801 et seq., set forth in 7 CFR part 12; and (2) Develop new or revised conservation plans.
Approach:
Under the terms of this agreement, USDA-ARS, with assistance from the RUSLE2 team (Clemson University, Middle Tennessee State University, and the University of Tennessee), will address bug removal and provide additional support for both the stand-alone and web app versions of RUSLE2. The priority of deliverables will be determined by the NRCS National Agronomist. These deliverables will include the tasks listed below. USDA-ARS agrees to follow the guidance of Giulio Ferruzzi.
The framework supporting the development of the Revised Universal Soil Loss Equation, Version 2 (RUSLE2), incorporates elements of a comprehensive research plan that involves further development of RUSLE2 technology through the following tasks:
USDA-ARS Tasks to be completed:
Task 1. Provide bug fix support to release new stand-alone versions of RUSLE2, address identified bugs associated with new releases of the NRCS RUSLE2 (with or without code enhancements), and resolve other issues that may appear after deployment.
Task 2. Continue developing 2D functionality (i.e., RUSLE2D and EphGEE) for both the stand-alone and web app versions of RUSLE2.
Task 3. Train key NRCS personnel on both the stand-alone and web app versions of NRCS RUSLE2.
USDA-ARS Tasks to be performed continually during this agreement:
Task 4. Provide ongoing technical support to NRCS, including bug repairs or other issues related to the RUSLE2 model that arise due to new code implemented under this contract.
Task 5. Keep the responsible NRCS personnel informed of any changes to the RUSLE2 model.
Task 6. Support both the stand-alone and web app versions of RUSLE2.