As you finalize your schedule for spring planting, field application of manure may be part of your plan if it was not done in the fall. Application of manure in the spring increases the efficiency of nitrogen use while decreasing the potential of nutrient leaching.
Michigan State University Extension provides the following myths and realities of spring manure application:
Myth: Manure spread in April will not be available to corn in June.
Reality: Nitrogen in manure comes in several forms including ammonium and organic. As the soil warms in the spring, up to half of the organic nitrogen converts to nitrogen that is readily available to the growing crop. If the manure was injected, this organic nitrogen is available along with most of the readily available ammonium fraction.
Myth: Manure is too variable to be a reliable source of nutrients for crops.
Reality: Manure is obviously more variable than commercial fertilizer, but it can be managed for efficient crop production. Agitation in storage prior to hauling manure to the fields improves the uniformity of nutrients. Take several manure samples as you are emptying a storage system and see how much the nutrients vary from the first loads to the latter loads. For a list of testing laboratories, click here. It is important to spread manure as uniformly as possible.
Myth: Manure nitrogen is in a form that is not available to plants.
Reality: Manure contains several forms of nitrogen (organic and ammonium), and all forms of manure nitrogen ultimately convert to available forms for plants.
Myth: Manure is good for the soil but it should not be considered a nutrient source.
Reality: Manure is a valuable source of nutrients that should be credited against fertilizer recommendations. Manure application rates have a major effect on the amount of nutrients provided to the field. Obviously there is a big difference in nutrients per acre when manure is being applied at 3, 6, or 9 thousand gallons per acre.
Keep in mind that many states have adopted new regulations covering land application of manure or have altered existing regulations. Before application, be sure you are familiar with local, state and federal regulations that apply to manure application in your area.
Other priorities before application include inspection of manure handling and application equipment to make sure it will function correctly. Replace or repair anything that needs to be fixed to prevent leaks and spills. Visit with neighbors to inform them of expected upcoming application dates and determine if there are days when manure application might be avoided.
Monitor weather forecasts before manure application and avoid applying immediately prior to predicted rainfall. In addition, it is always a good idea to have an emergency action. Keep telephone numbers and emergency contact numbers easily available. Manure spills can be disastrous and quick action is critical.
Proper manure application strategies and techniques at all times of year are vital to maximize manure value, comply with regulatory requirements, protect the environment, and foster good neighborhood relations.