Manure setbacks, how far is far enough?
Injected or immediately incorporated manure is always a good idea, but when surface applying be sure manure does not reach surface waters.
Remember the golden rule on spreading manure: do not let it reach surface waters. This can be achieved by the best decisions you can make based on weather, rates, application methods and field conditions.
The basics for surface applied unincorporated manure are, the applicator should observe a minimum of 150 foot setback from surface waters, including ditches and areas subject to flooding. If conservation measures, such as, vegetative buffers are in place they may be sufficient to protect surface waters from runoff. Following these recommendations will help achieve conformance with right to farm guidelines and provide nuisance protection. But they do not over ride common sense. The goal is to prevent manure from reaching surface water. If you are on a slope, using high rate of manure application, or on a field where conditions still allow manure runoff to reach surface waters, then the 150 foot setback and or vegetative buffer strip may still not be enough. In this scenario, selecting a different manure rate, utilizing a less risky field or waiting for an opportunity when manure can be incorporated may be a better decision.
For right to farm guidelines, if manure is incorporated within 48 hours the setbacks are not necessary. Quicker incorporation is always recommended to both preserve the nitrogen in the manure and ensure against a sudden rain event. Right to farm allows surface applied manure when no-till or hay field conditions make incorporation unfeasible.
Keeping records of manure applications, including field and weather conditions, will be the way to validate your actions. These are guidelines for right to farm protection. If you farm is under an NPDES permit then be sure to follow those requirements which are mandatory for compliance. Setbacks may also apply even for injected manure.
For a complete listing of right to farm guidelines for manure, visit Michigan Department of Agriculture & Rural Development’s Generally Accepted Agricultural and Management Practices.