ARS | Publication request: WHOLE-FARM PHOSPHORUS MANAGEMENT ON DAIRY FARMS

Submitted to: Wisconsin Fertilizer Aglime and Pest Management Conference
Publication Type: Proceedings
Publication Acceptance Date: January 17, 2002
Publication Date: N/A

Technical Abstract: The dairy industry is undergoing rapid change to remain economically viable. Many farms are expanding herd size and increasing the importation of feed. Greater livestock numbers on a fixed land base has increased the risk of soil nutrient buildup and environmental pollution. This paper provides a synopsis of the environmental concerns associated with agricultural phosphorus (P) and the legislative approaches to reduce P surplus and loss from animal operations. It also summarizes recent research results that show how P management in one dairy system component (e.g. feed) affects other system components (soils-crops) and how integrated, whole-farm P management may allow producers to better comply with the emerging P-based nutrient management regulations. Various options are available for improving the P management on dairy farms. The most immediate positive impact would be derived from reductions in the importation of unnecessary fertilizer and diet supplements. Reductions in P feeding by eliminating inorganic P supplements and selecting protein supplements of low P content would (1) result in less P imported and excreted in manure, and therefore reduce the cropland area needed for manure P recycling and (2) align the N:P ratio of manure to coincide more closely with N:P ratio of crops, thereby reducing the hazard of over application of P, buildup of soil test P, and runoff from manure-amended fields. The needed integrated approach to nutrient management on dairy farms necessitates close interaction between farmers and the feed and fertilizer consultants and veterinarians hired by farmers to make nutrient management decisions.