|Powell, J mark|
Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract only
Publication Acceptance Date: 11/9/2000
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Most dairy farms in the Northcentral and Northeastern U.S. continue to be land-based, that is, they produce most of their feed and recycle manure nutrients through crops. Many dairy farms in other regions rely more on feed importation. To remain economically viable, many dairy farms are increasing herd size and importing more and more feed. Excessive nutrient imports resulting in soil nutrient accumulation, runoff and the pollution of surface and ground waters are the most pressing environmental challenges facing many dairy systems. This paper examines key factors that affect phosphorus inputs and outputs, pathways, and flow rates on dairy farms. The paper will elucidate key relationships between feed, land management and P recycling, such as (1) between feed sufficiency and the ability of a farm's land base to recycle manure P; (2) between the feed P and the amount and forms of P excreted in manure; (3) between manure P excretion and the buildup of soil test P; and (4) between manure application, tillage and P runoff. It will show how improved P management in one production component (e.g., feed) affects P cycling in other production components (e.g., soils and crops) and the relative impact of each component's management on profitability and the environment. Improvements in P cycling on dairy farms must come from more unified approaches to technical assistance and educational programs that integrate nutrient management decisions.