December 6, 2013
Winter has come to Wisconsin. Cropland through most of the state is now frozen and / or snow covered. In Wisconsin, most permitted farms do not spread manure in the winter. There are however many livestock operations that are set up to, and need to spread manure frequently through the winter.
Winter manure spreading brings with it a host of challenges. Some challenges are purely physical, as in driving through deep snow, driving up steep slopes, knowing where to begin spreading as your last couple passes get covered with new snow, and – of course frozen equipment and frozen manure.
Another set of challenges with winter manure spreading tie directly to nutrient management. Your intent is to spread the correct amount of manure that will supply nutrients for next year’s crop; and, manage manure placement and timing so it stays in the field.
For your individual farm, do you understand the risks associated with spreading manure on frozen / snow covered ground?
Data gathered by UW Discovery Farms shows that when manure is applied one week or less before a runoff event, the losses of nitrogen and phosphorus are significantly increased even with relatively low application rates.
When manure is applied several weeks or months before runoff occurs, nutrient losses can be reduced by as much as 50 to 75 percent. Understanding the conditions that increase the risk of nutrient loss can help farmers better manage manure throughout the year.
In the late fall and early winter (October – December) in Wisconsin, fields are often harvested and may be frozen. However, there usually is not significant snow cover, concrete frost, or ice crusted soil that is common later in the winter. Manure applied during the time period before these conditions develop has a lower chance of contributing nutrients into surface water runoff than applications made later in the winter (February – March).
For more information: a 2-page article summarizing considerations for early manure applications has been developed and is available on our UW Discovery Farms website:
Written by Kevan Klingberg, Outreach Specialist firstname.lastname@example.org