Kentucky Nutrient Loss Science Assessment

Background The Mid-South states in the Mississippi-Atchafalaya River Basin (MARB) differ from Midwestern states in that they have significant pasture-based animal production systems in addition to row crop production; Kentucky alone has 3.8 million acres in pasture (USDA-NASS, 2012) with over 1.1 million beef cows and calves (KCA, 2018), ranking it the largest beef producing state east of the Mississippi River. Typical beef cattle (cow/calf) management in the Mid-South is pasture-based, with animals spending close to 100% of their time on pasture. Seasonal observations by Extension personnel indicate overgrazing of pastures resulting in denuded farmland (Barnes, 2017). Lack of pasture vegetation coupled with rolling topography in humid regions increases risk for sediment, nutrient, and pathogen losses to waterways. Kentucky’s nutrient reduction strategy currently specifies conservation practice effectiveness determination as an action item, yet this work has not been accomplished. Integrating practice efficiencies into Kentucky’s nutrient reduction strategy will move the Mid-South forward in the reduction of nutrient losses from agriculture. Methods The University of Kentucky (UK), will begin the science assessment process to support their nutrient reduction strategy. Building upon lessons learned from workshops held in Indiana and Arkansas through the previous WFF grant, UK will organize a series of workshops/workgroups to determine nitrogen and phosphorus reduction efficiencies for up to 10 water quality conservation practices. The top 10 practices to consider will be based on outputs developed under the previous WFF grant; however, the workshop attendees may include other promising conservation practices. Since animal agriculture is nearly 50% of the agricultural sales in the state, conservation practices dealing with animal agriculture will be considered. The results of the work on animal agriculture can be used to inform other HTF states where animal agriculture is prominent, yet little work has been done to quantify nutrient reductions from these activities. The organizing team will also evaluate the potential to advance the WFF animal agriculture priority. Outputs 1) Produce a report summarizing workshop findings and listing nitrogen and phosphorus reduction efficiencies for water quality conservation practices of importance in Kentucky. This is in direct alignment with output 6 of the University of Illinois grant proposal to the Walton Family Foundation. 2) Connect workshop findings to Kentucky’s nutrient reduction strategy. This output supports output 3 of the University of Illinois grant proposal to the Walton Family Foundation.