Careful manure management is a keystone of farm profitability and environmental stewardship. UW-Discovery Farms research has shown that timing of manure management is one factor that should be carefully considered to reduce nutrient losses from farming systems. Data have shown that the shorter the time between a manure application and a runoff event, the higher the risk for loss. While understanding what conditions could lead to a runoff event is important, a thorough understanding of landscape challenges in your area is also critical.
The areas listed here are some of the important things to consider when making decisions about manure management. This is not an exclusive list, it is meant to provide information gained from studies conducted by or in cooperation with UW-Discovery Farms over the past several years.
When the soil is frozen and/or snow covered, runoff from rain events or snowmelt events can have large nutrient loads if manure has not been carefully managed through the seasons. Knowing the timing and areas where spreading has a lower risk factor can help keep nutrients in place in the fields.
UW Discovery Farms data suggests that soil moisture content is a good predictor of runoff risk. Research has shown that a small amount of rain can trigger runoff if soil moisture content is above 35%.
In areas with carbonate bedrock near the soil surface, water quickly and easily infiltrates to the subsurface. Researchers found that groundwater in some areas of Wisconsin, including Calumet County, aquifers used for drinking-water supplies have a moderate to high risk of contamination. This susceptibility to contamination is largely dependent upon the thicknesses of the unlithified materials over the groundwater aquifers.
Assessing Hormones in Livestock Manure
Find more information on a study conducted in cooperation with UW Discovery Farms that examined the potential effects of hormones released from livestock manure in a variety of settings.