Effects of Unimproved Equine Manure Stacking on Soil and Groundwater Nutrients at Sites with Seasonally High Water

Project Overview

Project Type: Partnership
Funds awarded in 2018: $14,795.00
Projected End Date: 04/15/2020
Grant Recipient: Bucks County Conservation District
Region: Northeast
State: Pennsylvania
Project Leader:
Rachel Onuska
Bucks County Conservation District

Information Products


Not commodity specific


  • Animal Production: manure management
  • Crop Production: nutrient management
  • Education and Training: on-farm/ranch research

    Proposal abstract:

    Pennsylvania currently ranks 9th in horse population across the United States. Bucks County is located in southeastern Pennsylvania, a region that has seen a 9.3% growth in the horse population since 2012. Over the last 10 years, equine farms have become a significant portion of the Bucks County’s Conservation District’s (BCCD) soil and water conservation efforts.  Of the fourteen regulated farms in Bucks County, all are equine farms and 95% of BCCD’s farm complaints have been equine-farm related.

    Improper manure-stacking is a common concern on equine operations. Pennsylvania has specific regulations for manure-stacking; however, few studies have demonstrated groundwater contamination from stacked manure on earthen surfaces .  In addition, 62% of soils have a seasonal high water (SHWT) table 36 inches or less from the surface in Pennsylvania’s Bucks and Montgomery counties; however studies investigating leaching from manure- stacking on soils with SHWTs are currently lacking.

    Due to skepticism from equine farmers about potential groundwater contamination from manure, obtaining voluntary compliance with improved manure-stacking regulations has proven difficult. BCCD proposes to study nutrient leaching from unimproved equine manure stacking on soils with SHWTs with Delaware Valley University serving as the project’s technical adviser and Pennsylvania State University serving the project’s outreach partner.

    Results from the project will be used by the agricultural conservation community to increase awareness among equine farmers of groundwater concerns relating to improper manure-stacking. Scientific-based support of existing manure regulations will increase farmer buy-in to the groundwater contamination claim, removing a significant barrier to adoption of improved manure-stacking.

    Project objectives from proposal:

    Project Goal: Increase awareness of groundwater pollution relating to improper manure stacking and seasonal high water tables (SHWT) to increase equine farmers’ acceptance and implementation of improved manure stacking.

    The project will achieve the above goal with the following objectives:

    1.DWith Delaware Valley University serving as the technical advisor, conduct research on four equine farms to evaluate the extent that nitrogen and phosphorus from manure stacking on earthen surfaces contaminate SHWTs.

    2.DDevelop two educational tools that will highlight key results from the research, one in a format easily digested by equine farmers, and another in a format easily digestible by technicians working in the agriculture conservation sector.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.