Assessing the implications of chloride from land application of manure for Minnesota waterways


Rising chloride contamination in ground and surface waters is a growing concern in Minnesota. Previous studies estimate 87% of the chloride load originated from road salts, fertilizers, and wastewater treatments plants, and 6% from livestock manure. However, these estimates may be outdated as the livestock industry and manure application practices have evolved since these estimates of manure chloride concentrations were calculated in 2004. It also remains unclear how varying soil types affect the movement of chloride leaching following manure application. The aim of this study is to understand the movement of manure-based chloride from liquid and solid manures in Minnesota soils through a series of intact core leaching studies. Specifically, this project examines the magnitude of chloride leaching from swine and turkey manure application and compares it with synthetic potassium chloride fertilizer and a no nutrient control. The soil cores represent fine and medium textured soil.

What Did We Do?

    • Collected 24 12-inch soil columns from medium and fine-textured soils in Minnesota (Figure 1).
    • Collected swine and turkey manure from Minnesota farms
    • Analyzed soil pre- and post-leaching study for nutrient analysis (Cl, Bray P, NH4+, NO3, K, Organic Matter, pH, and Exchangeable Ca, Mg, Na, K)
    • Analyzed manure samples for nutrient analysis pre-application (Total N, P2O5, K2O, Cl)
    • Added water to cores until they reached field capacity
    • Applied manure using N-based application rates, and fertilizer using a K-based rate to 3 replicates
    • Simulated 2-in rainfall events on days 4, 12, and 18 post nutrient application
    • Collected and analyzed leachate for Cl, NH4+-N, and NO3-N
Figure 1: Setup of 12-inch PVC soil cores for leaching study

What Have We Learned?

    • How chloride concentration varies based on manure type and species
    • How the total amount of chloride applied via fertilizer application to cores varies by treatment
    • How manure-based chloride moves through soil
    • How fine and medium textured soil influences the movement of manure-based chloride
    • How chloride storage changed by soil type following the experiment (Figure 2)
      1. Medium textured soils had a greater change in chloride storage in both top and bottom layers compared to fine textured soils
      2. Manure additions increased chloride storage in both medium and fine textured soils
      3. Control soil cores experienced a loss in chloride storage following leaching
Figure 2: Change in soil chloride storage in each medium textured (left) and fine textured (right) soils by treatment. Positive values indicate a net gain in soil chloride, while negative values indicate a net loss in soil chloride following leaching.
Table 1: Total Cl concentration of liquid swine manure (lbs/1000 gallons), solid turkey litter, and synthetic KCl (lbs/ton) followed by total weight (g) of Cl added per core via application.

Cl (lbs/1000 gallons)

Cl (lbs/ton)

Cladded per core (g)













Future Plans

Our group would like to complete a second round of this study the following year on newly identified liquid and solid manure and an additional coarse textured soil type. Future attempts in creating chloride-based mass balances for the state of Minnesota will benefit from this study.


Matthew Belanger, Graduate Research Assistant, Dept of Soil, Water, and Climate, University of Minnesota

Corresponding author email address

Additional authors

Dr. Erin L. Cortus, Associate Professor and Extension Engineer, Dept of Bioproducts and Biosystems Engineering, University of Minnesota

Dr. Gary W. Feyereisen, Research Agricultural Engineer, USDA-ARS Soil & Water Mgt. Research Unit

Nancy Bohl Bormann, Graduate Research Assistant, Dept of Soil, Water, and Climate University of Minnesota

Dr. Melissa L. Wilson, Assistant Professor and Extension Specialist, Dept of Soil, Water, and Climate, University of Minnesota

Additional Information

Wilson Manure Management and Water Quality Lab Site


This project is funded through the University of Minnesota Water Resource Center’s Watershed Innovation Grants Program. We’d also like to thank Scott Cortus, Eddie Alto, Todd Schumacher, Dr. Pedro Urriola, and Thor Sellie for their assistance.