Submitted to: Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE)
Publication Type: Proceedings
Publication Acceptance Date: 4/10/2007
Publication Date: 6/28/2007
Citation: Rotz, C.A., Kleinman, P.J., Dell, C.J., Schmidt, J.P., Beegle, D. 2007. Environmental and Economic Comparisons of Manure Application Methods on Dairy Farms. Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE). Paper No. 074068, St. Joseph, MI:ASABE. Interpretive Summary: An interpretive summary is not required.
Technical Abstract: Field measurements and a farm simulation model were used to compare the environmental and economic impacts of using alternative manure application methods on dairy farms. The Integrated Farm System Model was able to represent the corn silage production, water balance, volatile ammonia N loss, nitrate N leaching loss, and P runoff losses measured in field plots with manure application treatments of no manure application, broadcast application without incorporation, broadcast application with tillage incorporation, band application with aeration, shallow disk injection, and high pressure injection. Measured and simulated results showed that incorporation of manure below the soil surface through tillage or injection reduced ammonia N losses but tended to increase nitrate leaching losses. Effects of the manure application strategy on P losses were less clear, but there was a trend toward less surface runoff loss of P with injection of manure and greater loss of sediment bound P when tillage was used to incorporate manure. Whole-farm simulation of each of the manure application strategies on a representative dairy farm in central Pennsylvania indicated that reductions in ammonia N loss and runoff loss of P can be obtained with the use of shallow disk injection without adversely affecting farm profitability. Use of broadcast application with tillage incorporation, band application with aeration, or high pressure injection reduced average annual farm net return by $34, $22, and $30/cow, respectively compared to broadcast application of manure without incorporation. Additional benefits such as odor reduction may also be obtained, which may help justify the additional production cost even when no direct economic benefit is received.