Experiential soil testing education program to reduce urban nutrient runoff in tennessee

Overview

This program addresses a gap in homeowner awareness about the water quality consequences of overfertilizing lawns and gardens in Tennessee. USGS SPARROW modeling indicates that urban land use contributes up to 40% of total phosphorus yield in some Tennessee HUC8 watersheds, yet many permitted municipalities lack the capacity to deliver evidence-based fertilizer guidance to residents at scale. By embedding soil testing tools and watershed education within the existing Tennessee Master Gardener network—which already spans 42 of the state's 95 counties—the program creates a scalable, peer-driven pathway for behavior change that complements broader statewide nutrient reduction efforts.

Technical specifications

• Program delivery channel: Tennessee Master Gardener framework, leveraging trained volunteers across 42 active county programs to reach urban and suburban homeowners
• Participant resources: Each participating program receives a soil probe and pre-paid soil tests so homeowners can collect and analyze samples directly
• Educational content: Localized stream quality information, general watershed education, and fertilizer recommendation guidance tied to soil test results
• Observation underpinning the approach: UT Soil, Plant, and Pest Center data (2015–2019) showing median soil test phosphorus in residential yards and gardens exceeded agricultural field levels in 19 of 20 sampled counties
• Measurement approach: Pre/post surveys assessing changes in understanding of overfertilization effects on water quality, knowledge gained in soil testing and interpretation, and self-reported behavior change in fertilizer source or rate decisions

Technology readiness level

The program concept is informed by existing observational data from the UT Soil, Plant, and Pest Center and builds on an established Extension and Master Gardener infrastructure that is already active in nearly half of Tennessee counties. The proposed validation phase will pilot the soil probe and pre-paid test distribution model through participating Master Gardener programs and measure outcomes via pre/post surveys focused on knowledge gains and behavior change. Future scaling would extend the model to additional counties and integrate with municipal stormwater and statewide nutrient reduction initiatives.