The balance of manure management

Authors: Young, Eric; Sherman, Jessica

Submitted to: Progressive Forage Grower
Publication Type: Trade Journal
Publication Acceptance Date: 11/11/2021
Publication Date: 11/18/2021
Citation: Young, E.O., Sherman, J.F. 2021. The balance of manure management. Progressive Forage Grower. January, issue 1. pg. 30-31.

Interpretive Summary:

Technical Abstract: Modern dairy production relies on capturing nutrient and production efficiencies for the animal and cropping sides of the business to optimize profitability. Manure management is an increasingly important economic and environmental aspect of dairy production. Manure nutrient content/speciation and total solids content can vary widely among farms and over time for individual farms, however manure is a critical source of crop nutrients and soil organic carbon. Managing a range of semi-solid and liquid manures is common on larger dairy farms. Technology for handling, transporting, and incorporating manure has quickly evolved and encompasses a large range of field application equipment and tillage combinations. While broadcast/surface application of manure is still common in hay and annual cropping systems, incorporating manure with some type of tillage captures more nitrogen (N) and phosphorus (P) and often reduces loss potential. Low disturbance manure incorporation (LDMI) applies manure via injection tools and/or enhancing infiltration of manure, while reducing soil disturbance compared to conventional tillage incorporation. Shallow disk injection and aeration-banding are LDMI methods using liquid manure and applicable to both corn and hay crops. USDA-ARS led research at the Marshfield Agricultural Research Station indicated shallow disk injection conserved more N for fall-applied manure in a corn-silage winter rye cover crop system. Corn yield for injected manure treatments did not differ from spring applied fertilizer N treatments (up to 180 lb N/acre) and maintained more surface residue than tillage incorporation. In rainfall-runoff field experiment with manure applied after first and third cutting of alfalfa-grass, shallow disk injection and aeration-banding significantly reduced N and P forms in runoff and maintained similar amounts of residue, alfalfa, and manure surface coverage. Another three-year experiment with alfalfa-grass indicated that LDMI had similar yields compared to broadcast application. In summary, LDMI has the potential to show promise for improving nutrient use efficiency in hay and corn systems, however longer-term research at is needed to better evaluate impacts of LDMI on forage yield and quality.