Calculating the value of manure as a fertilizer source

Manure has value on a field only if it offsets the need to purchase other nutrients or soil amendments. Manure has characteristics that may reduce its value relative to that of commercial chemical fertilizers. Manure can be a less dependable nitrogen source and is perceived as a source of weed seeds. Because manure is an unbalanced fertilizer source, meeting crop needs for one nutrient may result in application of too much or too little of other crop nutrients. Low nutrient concentration in manure increases handling and application costs. Manure has positive attributes as well. It is a slow-release fertilizer, and the organic material can improve soil quality.Ray Massey (Extension Professor, Commercial Agriculture Program), John Lory (Extension Associate Professor, Commercial Agriculture Program)New 12/97; Revised 6/13/We