Introduction to case studies
The case studies listed below demonstrate the economic and environmental value of, and strategies for, balancing imports versus exports of phosphorus entering and leaving Minnesota dairy and beef finishing farms.
When annual imports exceed exports, soil test phosphorus builds up to excessive levels, creating a risk of increased phosphorus in runoff. This problem is often more acute on farms with limited acreage for manure spreading relative to the number of livestock maintained.
Case study names and strategies
Strategy: Reduce net phosphorus imports and increase exports farm by acquiring more crop land through lease, purchase, or exchange.
Strategy: Eliminate starter fertilizer on high soil test phosphorus fields on beef feedlot farms.
Strategy: Eliminate starter fertilizer on high soil test phosphorus fields on dairy farms.
Strategy: Export dairy pen-pack manure.
Strategy: Incorporate manure immediately to conserve nitrogen and allow lower application rates to meet crop nitrogen needs.
Strategy: Reduce excessive soil-test phosphorus buildup by increasing crop production from existing acres for feed or sale.
Strategy: Reduce feed waste to reduce imported phosphorus.
Strategy: Reduce lactation phosphorus to NRC recommended levels.
Strategy: Stop importing poultry manure used for nitrogen fertilization.Funding: U.S. Environmental Protection Agency Clean Water Act Section 319 grant administered through the Minnesota Pollution Control Agency.