Manure is an excellent source of many essential plant nutrients that with proper management can meet all or a significant amount of the nutrient needs of most crops. The key to managing manure for maximum economic benefit from the nutrients and minimum environmental impact is to know exactly the amount and, in some cases, the form of nutrients in the manure. Unlike fertilizer, manure analysis and form can vary widely.
Even on a single farm, the analysis of manure can vary significantly over time due to management and weather conditions. Other factors affecting availability of manure nutrients include animal feeding, manure handling, manure storage, dilution with rain or wash water. Without a manure analysis an individual farmer has no way of knowing if the manure on his farm is close to the average analysis or if it is on the extreme ends of the range. More: Estimating Crop Available Nutrients in Manure
Finally, a single manure source can have a large variation if the manure is not thoroughly mixed before spreading. Manures must be analyzed on a regular basis especially when changes in management or conditions occur.
Page Authors: Douglas Beegle, Pennsylvania State University and John Peters, University of Wisconsin
Reviewers: Jerry Martin, Pennsylvania State University and Rick Koelsch, University of Nebraska