Manure nutrient management in cold climates

Authors: Young, Eric

Submitted to: Trade Journal Publication
Publication Type: Trade Journal
Publication Acceptance Date: 1/16/2020
Publication Date: 1/23/2020
Citation: Young, E.O. 2020. Manure nutrient management in cold climates. Trade Journal Publication. February 2020. Pg. 16-17.

Interpretive Summary:

Technical Abstract: Crop production in cold climates involves a short growing season with extended periods of high runoff potential that complicate manure nutrient management. Nitrogen (N) and phosphorus (P) are especially vulnerable to surface runoff during snow melt and storm events. The combination of frozen/partially frozen soils coupled with snow melt and/or intense precipitation events can contribute to high runoff N and P concentrations. Manure application method (surface vs. incorporation) has a major impact on N and P runoff loss risk. Compared to surface application, incorporation/injection of manure increases soil N/P availability and crop yield potential while mitigating runoff losses. Tillage incorporation of manure can effectively reduce surface runoff N and P loss potential but increase erosion/particulate nutrient loss compared to surface application or lower disturbance methods. Manure characteristics also affect nutrient loss potential. Nutrient and physical characteristics vary widely among livestock manures (and at the individual farm level) depending on livestock species, age, diet, manure handling and other factors. More liquid manures can be particularly vulnerable to transport in snow melt or saturated soils. Applying manure to unfrozen soils during the growing season can increase nutrient use efficiency and lower runoff loss risk compared to late fall/winter/early spring application. Targeting application to growing crops (hay, cover crops, small grains, corn) and injection prior to planting annual or perennial forage crops can help utilize manure nutrients more efficiently while mitigating environmental risk.