Manure Management Task Force

Wisconsin Association of Lakes Emeritus Director Lisa Conley represents all our lakes on this important task force that will develop strategies to minimize manure runoff and protect our water resources.

Manure is rich in nutrients (such as phosphorus) and is commonly spread on farm fields as a fertilizer. Nutrients, especially phosphorus, often flow into our lakes as polluted runoff and are a key factor in lake quality decline. There are several ways manure can become a detrimental source of phosphorus in our lakes:

• After world War II, commercial phosphorus had been used in dairy feed and on cropland. Phosphorus has built up in our soils from decades of applying phosphorus whether or not fields have needed the nutrient. Increasing amounts of phosphorus are being released from these over saturated soils into our waters.
• Erosion and leaching move the phosphorus from the uplands into the waters of our watersheds.
• Acute manure spills— from manure spread on impermeable frozen ground or rain washing liquid manure into our lakes—are also a source of phosphorus.