November 5, 1999 | By: Haven Miller

A study produced by the University of Kentucky Cooperative Extension Service offers new information on the potential for livestock and poultry manure use in counties. The study assesses the degree to which soil nutrients removed annually from fields and pastures could be re-supplied by manure.

Using data from several government and university sources, a committee of UK Extension specialists and agents calculated the proportion of nutrients removed annually by harvested crops and grazed forages. Then they compared these numbers to the amount of livestock and poultry manure produced each year. Results show nutrient balance percentages for nitrogen, phosphate, and potash in each of the state's counties. For example, if the nitrogen removed by a county's crops and forages was 10,000 tons, and total recoverable nitrogen from manure was 2,500 tons, the county's nutrient balance for nitrogen would be 25 percent.

"Our goal was to come up with something useful," said Richard Coffey, Extension animal scientist and committee co-chair. "I think the report gives a clearer picture of overall potential for manure use. We recognize the study's limitations, and caution that it's not a guideline for individual farms, but it may offer producers or county planners a place to start."

Coffey said nutrient balance percentages generated for specific counties should not be looked at as indications of either success or failure in manure management practices.

"If a county has a particularly high number for nitrogen or phosphate, that does not necessarily mean there are problems, or that you can't find an area to put in a new operation. The same would be true of a county with a particularly low number."

Among the committee's findings is an indication that crops and forages in 84 of the state's 120 counties have the capacity to remove more than two million additional pounds of nitrogen above the amount that could be supplied by manure. Crops and forages in 57 counties have the capacity to remove more than one million additional pounds of phosphate. Less than 25 percent of potash removed yearly by crops and forages could be supplied by livestock and poultry manure in 114 counties.

In issuing the report, the committee recognized some producers may not want to use livestock manure on their land, and not all manure is used as fertilizer. The committee emphasized the report is not a guideline for restrictions, but rather a snapshot of the overall picture to be used as a starting point for community discussion and planning.

"Our hope is that this report provides an objective look at whether we have areas of concern, and I think it will be helpful to local communities in addressing issues concerning animal operations," said Ron Bowman, Nelson County Extension agent and committee co-chair. Calculations for the crops portion of the study included data on corn, corn silage, soybeans, wheat, alfalfa, tobacco, barley, and sorghum. Calculations for animal manure included data on beef, dairy, swine, and poultry. Grazing was taken into account, as well as a recognition that the amount of applied nitrogen effectively utilized by the soil is less than 100 percent.

Copies of the report are available through your county Extension office. Publication IP-57, "Potential for Livestock and Poultry Manure to Provide the Nutrients Removed by Crops and Forages in Kentucky," is the shorter version which includes a summary of findings. IP-56, "Assessment of the Potential for Livestock and Poultry Manure to Provide the Nutrients Removed by Crops and Forages in Kentucky," is the longer, more detailed version with a complete listing of tables and charts.


Writer: Haven Miller (606) 257-3784
Source: Richard Coffey 270-365-7541