Development of Agricultural Conservation Reduction Estimator (ACRE), a simple field-scale conservation planning and evaluation tool

The United States spends billions of dollars each year on subsidized conservation practices to reduce sediment and nutrient pollution from agricultural lands with little assessment of how much those loads were reduced. A variety of tools are available to predict the effects of conservation practices, but these either suffer from a lack of accuracy due to limited monitoring data, or are model-based and too complex for use by conservation planners. In this research, we detail the development of a simple tool to fill this need, called the Agricultural Conservation Reduction Estimator (ACRE). ACRE is driven by an extensive national database of export coefficients developed using the Texas Best management practice Evaluation Tool (TBET) and Soil and Water Assessment Tool (SWAT) models combined with conservation practice efficiencies derived from a mixture of literature values and model simulations. The previously calibrated and validated TBET/SWAT was applied nationally using data from the National Agricultural Model, an effort by the USDA Agricultural Research Service to construct publicly available data sets for modeling at national scale. ACRE uses distributional information from both model predictions and literature estimates to perform a Monte-Carlo based estimate of sediment and nutrient loads (with confidence limits) from cultivated cropland. ACRE meets an important need by providing science-based estimates of conservation practice benefits at the field scale to producers and conservation planners through a very simple tool.