Reduce your environmental hoofprint

You hear about it all the time in the news or on television, and your kids probably learn about it in school. The environment. Believe it or not, even your cows are leaving behind an environmental hoofprint.

A recent study done by the Agricultural Research Service (ARS), a USDA research agency, examined the environmental impact of solid dairy manure, liquid dairy manure, and commercial fertilizer on phosphorus contamination in watersheds. Results showed that solid dairy manure was the least harmful in excreting phosphorus followed by commercial fertilizer and, finally, liquid manure.

Twenty-four soil columns were evaluated after being spread with either solid or liquid manure or monoammonium phosphate (MAP), a commercial fertilizer. These columns were irrigated 13 times over the nine-week test period and the leachate, liquid drained out of the soil, was collected and analyzed for concentrations of phosphorus, carbon, calcium, iron, and manganese.

ARS scientists Tarkalson and Leytem found that phosphorus in commercial fertilizer was more mobile than phosphorus in the solid manure. They also found that phosphorus moved through soil in much larger quantities with liquid manure versus the other two fertilizers.

What does this mean for farmers?

If you’re concerned about watersheds in your area, you can take steps to reduce your environmental impact. A few solutions include spreading your manure across a larger area of land, avoid spreading manure near waterways (however small), trying not to spread on the same piece of land repeatedly, and investigating new options in manure management.

Midwest Manure Summit at Lambeau Field

Capturing and managing the value in your farm’s waste stream was the focus of the Midwest Manure Summit held March 24 and 25, 2009, at Lambeau Field, Green Bay, Wis. Two full days of featured speakers educated producers, consultants, and others interested in manure management. Optional tours of the historic Lambeau Field were also a popular draw of the conference.

Frank Mitloehner of University of California-Davis took several questions after his discussion on odor management. Mitloehner described mitigation strategies for reducing odor on farms, as well as his experiences with projects on UC-Davis’ campus, and a village in Germany that will, and have, reduced odors. Both of these systems generated power through the use of methane digestion, and the German village is now off of the power grid.

Another speaker, Keri Cantrell of the USDA-ARS in South Carolina, outlined research on emerging technologies that turn waste into energy and are not yet commercially available. Instead of methane digestion, Cantrell described a potential for thermo-chemical conversions such as pyrolysis. Pyrolysis could greatly reduce hauling involved with typical manure management and produce a product known as bio-char which could be used as a soil amendment. If implemented, these technologies have the potential to allow farms to expand animal units without adding land needed for nutrient management planning.

Proceedings of the entire conference are expected to be available online shortly on the Midwest Manure Summit website.