Incorporating manure into the soil fertility plan


Farmers across the country are getting creative in trying to find the answer to high fertilizer prices and tight supply for 2022.

Including manure can be a part of the plan to decrease the fertilizer bill, but there are some considerations when including it as part of the overall fertility plan, says Peter “Wheat Pete” Johnson.

Manure is an incredible soil amendment, but it has limitations when counting on it to provide enough nitrogen in a fertilizer calculation.

“Growers who have a lot of manure who maybe used to not give manure the full nitrogen credit are stepping back and saying maybe we’ll give it more nitrogen credit this year,” says Johnson.

Figuring out how much N the manure accounts for is an interesting question, says Johnson, and the considerations include type of manure, when will it be applied, and how will it be applied.

In the interview below, Johnson gives an example of a neighbour applying manure before a corn crop goes in next year, and whether or not the supposed 100 lb N credit can be relied on.

“Cattle manure, whether it’s beef or it’s dairy, and particularly if it’s solid manure, but even if it’s liquid manure, we really don’t see the full amount of the nitrogen we would expect in that first year of application,” says Johnson.

Poultry manure is like gold, says Johnson, despite the smell, which is valuable free ammonia. The organic portion of poultry manure is more stable than dairy manure, because of the urease enzyme in the dairy or beef manure that “blows nitrogen off” says Johnson. Plus, with poultry manure, there’s more N per tonne so hauling it is economical.

Hog manure lands somewhere in between for N credit, but on a one-time basis for application it’s closer to beef or dairy manure.

Soil moisture and time of application absolutely matter, as does how many years in a row manure’s been applied, explains Johnson, in the interview below.

Another consideration is how much to apply, and as Johnson explains, using manure to supply the full amount of N to a crop can over-supply the phosphorus to that crop, which can be a huge concern.

Listen to the full conversation between Johnson and Haney:


The Agronomists, Ep 49: Don Flaten and Dale Cowan on soil amendments

Wheat Pete’s Word, Dec 1: Corn height, sticky snow, stuck plows, and not so magical manure

Wheat Pete’s Word, Dec 8: More magical manure, corn bets, N credits, and wrapping up harvest

Please register to read and comment.


Register for a RealAgriculture account to manage your Shortcut menu instead of the default.