Scope 27: 104B State Water Resources Research Institute Program 2016 - 2021-Lawn Establishment in Kentucky: Balancing Green Laws with Waterbody Eutrophication Risks

Excess phosphorus (P) in the environment can cause eutrophication of water bodies and lead to hazardous and nuisance algal blooms (HNABs). These HNABs can lead to economic declines in recreational areas associated with lakes and streams as well as development in these areas. Previous research at the University of Kentucky has demonstrated that 79% of soil test P (STP) levels from urban areas across the Commonwealth have a high risk of water soluble P entering the environment, while only 33% of agricultural STP levels have a high risk. A common practice of turfgrass establishment in urban areas is to apply a "starter" fertilizer that has a high P content. Starter fertilizers are typically applied immediately after seeding with the intention of assisting the new seedlings to meet their demands for readily available nutrients until the plant's root system develops. Phosphorus is a key component of ATP (adenosine triphosphate), an energy-rich compound produced during the light reaction of photosynthesis. ATP is the energy currency used by plant cells for various metabolic processes, such as the synthesis of carbohydrates. Personal communications with fertilizer vendors in the Bluegrass physiographic region indicate that they recommend an application of P fertilizer regardless of what the STP levels are in the soil. Very few studies exist regarding the amount of P required to establish turfgrass. Those that do exist, were conducted in the upper Midwest and Mid-Atlantic regions of the US, where the soils are very different from the phosphate rich loess and limestone derived soils the Bluegrass, the most populated area of Kentucky. We propose to determine if a "Starter P" fertilizer is needed to establish the most common species of turfgrass in Kentucky (fescue), evaluate the runoff quality effects of applying "Starter P," and develop guidelines/recommendations for the application of "starter" fertilizers for the Kentucky turfgrass industry. These recommendations will be shared with approximately 1000 lawn and landscape industry professionals via the annual UK Turf and Landscape Short Course held in February, and to over 400 participants in the annual UK Turfgrass Field Day in July. In addition, we will present this information to the municipal separate storm sewer system regulated communities (MS4s) across the state at the Kentucky Stormwater Association annual conference, county Cooperative Extension Service (CES) agents via Water Wednesday webinar series and incorporated into the UK CES Master Gardener training programs.