Winter Manure Management Tips

OMAHA (DTN) -- While snow at Christmas makes a beautiful setting, it does not make for good manure application weather.

One of the rules of manure application is to spread manure whenever weather and field conditions allow. Rarely does perfect manure application weather occur and it does not last for very long.

This late fall in most of the Midwest, the application window has been wider with relatively no snow cover and mild temperatures. At some point, however, this will likely change.

Producers need to keep several factors in mind for winter manure application. In a report titled "Tips for Winter Manure Management," University of Nebraska-Lincoln (UNL) Extension detailed the do's and don'ts of application: (https://water.unl.edu/…).

FACTORS TO CONSIDER

Producers need to test their soil and manure nutrient concentrations to guide their decisions on where manure should be applied. If possible, avoid applying manure on fields with slopes as this land presents greater risk for erosion and runoff.

Try to apply manure on ground with at least 30% crop residue cover as this reduces the chances of manure runoff during heavy rains and snowmelt. Another consideration would be to apply manure on coarse-textured soils as fine-textured soils have more infiltration rates and reduce the risk for nutrient runoff losses.

According to the UNL report, it is a best practice to apply manure outside of winter. However, application in winter can be done with low risk for runoff when certain conditions are met.

In general, manure application should be avoided when fields are snow-covered. If manure must be applied then or when the soil is frozen, it is critical to recognize the runoff risk associated with solid versus liquid manures before making application decisions.

DIFFERENT MANURE, DIFFERENT RULES

For liquid manure, it is not recommended to make an application to soil frozen beyond the top layer as this poses a high risk of nutrient loss through runoff. However, if conditions cause soil to freeze overnight and thaw during the day, application will likely create little risk for runoff.

Producers should watch the application field so the application can be discontinued if runoff does happen, according to the UNL report.

For solid manures, application to frozen soils can likely be done with little risk of runoff when precipitation is not predicted and the rules of where to apply manure are followed.

With either type of manure application, producers are encouraged to monitor the 10-day weather forecast and avoid applying manure before possible major precipitation events to avoid potential nutrient runoff. Avoid manure application for at least 24 hours before a forecasted precipitation event -- or even longer if possible.

Manure application should never exceed the needs of the crops and soils receiving them, regardless of the time of year. Again, sampling and testing soils and manure sources to determine the maximum rate of manure needed is recommended.

RESIDUAL N LEFT

Increased residual nitrate-nitrogen concentrations in some Nebraska soils might be present after lower-than-normal precipitation throughout much of the state in 2023. Repeated manure applications on a field without testing the soil can lead to a buildup of soil phosphorus, which increases the risk of losing this nutrient to surface water during runoff and erosion.

Another rule to follow when applying manure is do not apply near water sources. This rule should be followed year around, according to the report.

When in doubt about rate, method, location or timing of manure application, please seek guidance from trusted and knowledgeable experts. This could be the Nebraska Department of Environment and Energy (NDEE), Natural Resources Conservation Service (NRCS) or your local UNL Extension educator, or similar offices in other states.

Russ Quinn can be reached at Russ.Quinn@dtn.com

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