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.