It wasn’t that long ago when manure was thought of as a waste product. Recommendations were to dump it over the bank and use commercial fertilizer for crops. Many loads of manure got dumped into streams, so it would wash away. Out of sight, out of mind!
Manure may be a biological waste from an animal, but it shouldn’t be discarded in a poop-like manner.
Cow manure will supply your soil with organic matter, phosphorus, nitrogen and potassium. Manure contains organic matter that is nutrient rich and readily decomposes to release those nutrients over time.
One cow averages about 20 tons of manure per year. An application rate of 20 tons of manure per acre is realistic and will provide your soils with many nutrients. Soil, manure or leaf tissue tests will confirm what you need and how much to apply for the crops being grown. The organic matter fraction will improve the cation exchange capacity and possibly the pH of the soil. It has been shown where soils that received manure actually had better tilth and increased pore space.
The type of barn and animal housing makes a difference in manure types. Solid manures come from bedded pack, tie stalls and stanchion barns, where chocolate milkshake consistency manure comes from free stall barns. Cattle on pasture use the direct deposit method. They give the cow pie back to the pasture where they just harvested some grass, a fair exchange I believe.
How the manure is stored will also make a difference in the amount of nutrients lost or saved.
If manure is stored in an earthen pit, concrete tank or large big blue steel tank, the manure is stored without oxygen and will go anaerobic. A crust will form over the top of the manure and the nutrients such as nitrogen will be less likely to volatilize and go into the atmosphere.
Rich Redman is a retired District Conservationist for the USDA Natural Resources Conservation Service and an avid outdoorsman. His column will appear regularly. He may be reached at firstname.lastname@example.org.