Submitted to: Agricultural and Environmental Letters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/2/2017
Publication Date: 2/23/2017
Publication URL: https://handle.nal.usda.gov/10113/5801829
Citation: Duncan, E.W., Kleinman, P.J., Beegle, D.B., Rotz, C.A. 2017. Coupling dairy manure storage with injection to improve nitrogen management: whole-farm simulation using the integrated farm system Model. Agricultural and Environmental Letters. doi:10.2134/ael2016.12.0048.
Interpretive Summary: Farmers receive pressure to apply manure one time per year in the spring. Farms in the Chesapeake Bay Watershed range from no manure storage to some storage. Through modeling, it was determined that injecting dairy manure in combination with 6 months of storage provided the best environmental and economic results.
Technical Abstract: Application of livestock manure to farm soils represents a priority nutrient management concern in the Chesapeake Bay Watershed. Historically strong emphasis has been placed on adding manure storage to dairy operations, and, there has been recognition that manure application methods can be improved. The Integrated Farm System Model was used to simulate manure management on a typical Pennsylvania dairy farm (100 milking cows, 80 ha). Converting the operation from daily haul to 6 months of storage with broadcast application did not substantially change N losses to the environment. However, switching to manure injection conserved ammonium-N and improved manure N use efficiency by crops, even though it slightly exacerbated nitrate-N leaching. Increasing manure storage from 6 to 12 months and injecting manure reduced nitrate-N leaching by 38% due to better timing of manure application to crop growth, but lowered annual net returns. Overall, manure injection and 6-months of storage resulted in the best combination of profit and environmental outcome.