Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: June 29, 2001
Publication Date: N/A
Technical Abstract: One of the emerging issues for dairy farmers is the need to improve nutrient management. Nutrient accumulation in the soil, recognition of ground and surface water contamination and air quality concerns, and concentration of animal feeding operations have all contributed to this heightened environmental awareness of farmers and the public. Regulations are being promulgated in several States to reduce the likelihood of air an water quality degradation. Dairy cows convert 20 to 30% of their N intake into milk N, and the remainder is excreted as organic and inorganic N in urine and dung. Proper feed composition and N content reduces N excretion in urine, which is the most subject to loss by ammonia volatilization and nitrate leaching. Deeply rooted perennials reduce nitrate leaching losses and may be most important to establish on certain soils, such as tile- drained land, sandy soils, and shallow soil over permeable subsoil. Legumes shelp balance N cycling by utilizing both inorganic N from soil and atmospheric dinitrogen gas for growth, and by returning more newly fixed N to soils with smaller N supply. A common problem on dairy farms is accumulation of soil P, which may greatly increase the risk of P runoff to surface water. Lowering P concentrations in dairy rations will help reduce this buildup, but many farms also will need to reduce rates of manure application. Problems remain in applying research results to farm situations. Barriers to adoption of improved nutrient management need to be identified and overcome. There are several areas of research that should be pursued to learn how to optimize N retention and minimize P accumulation on dairy farms.