Manure Management

The farm community within the Mid-Atlantic footprint produce and use manure from varying sources for fertilizer in their crop production.  Operations producing manure use it themselves or move it through state transportation agreements to other producers.  Farmers recognize the value of manure in their production systems.  Getting the most value from manure requires understanding the basics of manure management.  It's a good source of nutrients, but it needs to be handled correctly and applied in a timely fashion to gain the most value.

The following management points should considered when using manure as a fertilizer:

• Manure Analysis. This is an absolute necessity for determining the nutrient value of the type and source of manure.  The type of dairy, beef, and poultry will vary based on feed source and animal size.  You need to know the amount of each nutrient to make accurate calculations for nutrient addition.
• Book Values.  Don't rely on book values.  There are publications which indicate typical analyses, but the management practices will determine the nutrient content.  Send a composite sample of each manure type to a lab for analysis.
• Time of Application.  The closer you are to planting time will provide the most efficient use of the applied nitrogen contained in the manure.  The longer the period between application and planting will allow for loss of valuable nitrogen contained in the manure.
• Injection/Incorporation.  Applying manure to the soil surface, will allow for loss of a portion of ammonia nitrogen through volatilization.  The longer the amount of time on the soil surface, the more the loss.  Incorporating or injecting will reduce the amount of nitrogen loss.  
• Weather Conditions.  Following the application of manure, if it turns warm and wet for long periods, you can figure a good portion of the nitrogen in the manure will be lost.  This needs to be accounted for when determining the amount of commercial nitrogen applied.  The use of a PSNT (pre sidedress nitrogen test) should be used when applying manure prior to applying additional nitrogen sources.
• Soil Acidity.  The application of large amounts of manure can increase soil acidity (lower pH) if there is significant nitrogen content.  Each pound of N contributes to soil acidity.  The pH level of the soil can affect the availability of plant nutrients.
• Nutrient Levels.  Yearly application of manure to the same fields can lead to a stopping point for applying nutrients, especially phosphorus.  Soil tests are needed to monitor P contents in the soil.  Once phosphorus levels reach a "very high" point, no more is recommended to be applied.  This is monitored by state nutrient management programs.