|Rotz, Clarence - Al|
Submitted to: International Silage Conference
Publication Type: Proceedings
Publication Acceptance Date: 7/30/1999
Publication Date: N/A
Citation: Johnson, L.M., Harrison, J.H., Rotz, C.A. 1999. The effect of altering the amount of corn and grass acreage on whole farm economics and nutrient management - using a computer simulation model (DAFOSYM). In Proceedings 12th International Silage Conference. p. 189-190. Interpretive Summary:
Technical Abstract: Environmental concerns have become an issue in recent years, and dairy operations are beginning to have strict manure management regulations imposed upon them in the United States and Europe. Economically favorable farm management practices are not necessarily environmentally friendly. Therefore, it is beneficial to evaluate how a new management practice effects the economics and nutrient balance of the whole farm prior to adoption of the practice. A dynamic computer model (DAFOSYM, Dairy Forage System Model) was used to determine how the ratio of grass silage and corn silage acreage affect profitability and nutrient balance on large- and medium-sized dairy farms in the Pacific Northwest. Simulations with 1/3 versus 2/3 of the total acreage planted in corn predicted different outcomes between the large- and medium-sized farms. On the medium farm, where the level of milk production was not maximized in the model, there was a 7% reduction in feed expenses and a resulting increase in farm profit. Nitrogen flow differed between simulations with 22% more N being leached in the ground water when 2/3 of the acreage was planted in corn. An increase in corn acreage on the large farm was economically unfavorable when milk production was maximized in the model. Unused soil N increased 39% when corn acreage was increased. This can be attributed to the greater application rates of N fertilizer and to less N being removed compared to the grass crop.