Placing Value in Manure Management

The average weight, well-fed cow produces 20 ton of manure per year.

This contains approximately 200 lbs of nitrogen, 56 lbs of phosphate and 150 lbs of potash. You can easily calculate the dollar value by multiplying these values by your unit fertilizer cost per pound.

Approximately 50% of the N is in the solids and 50% in the liquid fraction, most of the P is in the solids and most of the K in the liquid.

All of the nitrogen in the liquid fraction is soluble, readily available to crops, and easily lost as ammonia to the atmosphere if not incorporated, and as nitrate through leaching if applied at rates exceeding crop demand. The N in the solid fraction is released slowly over a number of years.

Most of the phosphorus lost from fields is through surface erosion. Leaching of phosphorus may occur on heavily manured fields.

Spreading manure without early incorporation and applying excessive amounts wastes money, and causes environmental pollution.


Stephen J. Herbert

Dept. of Plant and Soil Sciences

University of Massachusetts Amherst

Crops, Dairy, Livestock News. Vol. 3:2, Winter 1998-99

 Copyright or other proprietary statement goes here.
For problems or questions regarding this web contact [ProjectEmail].
Last updated: 11/11/02.