Manure Fertilizer

Manures are a time-tested valuable source of nutrients and organic matter for soils used to produce vegetables. In recent years, interest in manures as nutrient sources has increased. The rise in interest in organic crop production has led to more emphasis on manures and their use in crop production.

Here's an outline of some of the major management considerations when using manure on your farm.

Management Tips

  1. Obtain manures as close as possible to land application time, especially if you have no means to cover it. For winter application, apply after soil has cooled to less than 50degF.
  2. Have manures accurately sampled and analyzed for nutrient content, at least for nitrogen (N) and phosphorous (P). Use a locally developed system to determine the nutrient credits toward the crop's nutrient needs.
  3. Apply manure at the recommended rate and no more. Excessive rates of manure could result in excessive nutrients being made available during the season (too-lush growth and reduced yields and quality) or there could be large amounts of nutrients available for leaching during the season or afterwards.
  4. Nutrients in manures can lead to pollution just as easy as nutrients in synthetic fertilizers. The organic nitrogen in manure is rapidly converted to nitrate in warm soils and this nitrate from manure now behaves just like nitrate from any synthetic fertilizer. Incorporate manure soon after application to avoid N volatilization or erosion losses of manure to streams or rivers. Apply the manure in the crop beds and avoid, if possible, broadcasting over crop alleys and drive roads in the field. Apply manure only under the plastic mulch and not in the row middles.
  5. Use soil tests to determine nutrient application rates and when in short supply, apply manure on the most nutrientpoor soils first.
  6. Apply manures accurately with a carefully calibrated spreader. If using mulch, apply only what can be mulched within a day of application.
  7. Rotate manure applications from field to field. Avoid applying manure to the same fields year after year. This practice can lead to buildup of nutrients in the soil that could result in contamination from leaching or erosion of nutrient laden soil into surface water. Even phosphorus could leach in very coarse sandy soils.
  8. Know the nutrient requirement of your crop and apply the nutrients in the needed amounts only. Use synthetic nutrients or additional organic sources of specific nutrients to supplement nutrients not being supplied from manure.

Remember: manure is a good nutrient resource for vegetable production when utilized properly, but can pose a risk if used improperly in environmentally sensitive areas.