Long‐term simulations of agricultural watersheds have often been done assuming constant land use over time, but this is not a realistic assumption for many agricultural regions. This paper presents the soil and water assessment tool (SWAT)‐Landuse Update Tool (LUT), a standalone, user‐friendly desktop‐based tool for updating land use in the SWAT model that allows users to process multi‐year land use data. SWAT‐LUT is compatible with several SWAT model interfaces, provides users with several options to easily prepare and incorporate land use changes (LUCs) over a simulation period, and allows users to incorporate past or emerging land use categories. Incorporation of LUCs is expected to provide realistic model parameterization and scenario simulations. SWAT‐LUT is a public domain interface written in Python programming language. Two applications at the Fort Cobb Reservoir Experimental Watershed located in Oklahoma and pertinent results are provided to demonstrate its use. Incorporating LUCs related to implementation of recommended conservation practices over the years reduced discharge, evapotranspiration, sediment, total nitrogen, and total phosphorus loads by 59%, 9%, 68%, 53%, and 88%, respectively. The user’s manual is included in this article as Supporting Information. The SWAT‐LUT executable file and an example SWAT project with three land use rasters and the user’s manual are available at the United States Department of Agriculture‐Agricultural Research Service Grazinglands Research Laboratory website under Software. Editor’s note: This paper is part of the featured series on Optimizing Ogallala Aquifer Water Use to Sustain Food Systems. See the February 2019 issue for the introduction and background to the series.

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No‐till is one of the common conservation practices implemented in the Fort Cobb Reservoir Watershed (FCREW) located in central Oklahoma to improve soil and water resources while ensuring sustainable crop production. In this study, we used the recently developed Multi‐Objective Evolutionary Algorithm for the Soil and Water Assessment Tool model (SWAT‐MEA) to determine the optimal spatial placement of crop management systems when converting from conventional tillage to no‐till in the FCREW. A previously calibrated and validated Soil Water and Assessment Tool (SWAT) model for the FCREW for conventionally tilled land under winter wheat (Triticum aestivum L.), sorghum (Sorghum bicolor L.), and peanuts (Arachis hypogaea L.) cropping system was used. The objective functions for this study were maximizing crop yield ranks while minimizing sediment, total P (TP), and total N (TN) yield loads. Four modifications made in the SWAT‐MEA in order to achieve the defined goal of this study include an automated process of conversion from conventional to no‐till, ability to use crop yield ranks in the optimization process and to sum up species of N and P to TN and TP, and creation of a public domain standalone executable. Results indicated that converting from a conventionally tilled to no‐till system under optimal placement of crop management systems reduced TN, TP, and sediment yield losses by 45, 32, and 65%, respectively, while crop yields were not significantly affected. Overall, this case study shows that the SWAT‐MEA was able to successfully identify the optimal placement of crop management systems under no‐till condition and can be used for decision making.