Chloride in Livestock and Poultry Manure Samples in the U.S. Upper Midwest

Highlights Chloride was quantified in ~900 samples to determine its range in the manure of prominent livestock production systems. Median chloride concentrations were greater in liquid than solid manure samples (dry basis). Chloride was strongly correlated with sodium, nitrogen, and potassium in manure, especially liquid manure. ABSTRACT. This work describes chloride content in Upper Midwest manure samples by livestock production systems (dairy, beef, swine, poultry) and manure types (liquid, solid). This work examines the relationships between chloride and other manure analytes (moisture, total N, P, K, Ca, Fe, Mg, Na, S, Zn, Mn, and Cu). A survey of approximately 900 samples collected from Minnesota and regional farms was conducted between 2021 and 2023. A commercial laboratory conducted routine nutrient analysis and analyzed chloride by potentiometric titration. Descriptive statistics for liquid dairy and swine, and solid dairy, beef, and poultry manure samples are provided on a wet basis and dry basis. Median dry basis chloride concentrations were greater for liquid manure samples than solid manures. There were strong correlations between concentrations of chloride and sodium, potassium and nitrogen, especially for liquid manures. These correlations are discussed relative to potential chloride sources, including feed, water, disinfectants, and bedding. These data support manure nutrient management planning and modeling efforts.