Farm Transitions: Valuing Sustainable Practices—Alfalfa Nitrogen Credit

A fair stand of alfalfa on medium-textured soil can provide 160 lbs./acre of nitrogen to the corn crop that comes after it (1). Using a 2012 nitrogen price of $0.60 per lb. (2):

  • 160 lbs. nitrogen/acre x $0.60/lb = $96/acre nitrogen credit from the alfalfa crop

Because breakdown of plant matter in the soil takes place gradually over time, the plowed-down alfalfa crop will also supply nitrogen to the second year of corn after the alfalfa is plowed down.

  • 50 lbs. nitrogen/acre 2nd-year credit (1) x $0.60/lb (2) = $30/acre 2nd-year credit from the alfalfa crop.

References:

(1) Using Legumes as a Nitrogen Source. June 1997. L.G. Bundy, K.A. Kelling and L. Ward Good. University of Wisconsin Extension, publication #A3517. http://ipcm.wisc.edu/download/pubsNM/Usinglegumes.pdf

(2) Fertilizer Use and Price. Reports from the Economic Research Service, USDA.
www.ers.usda.gov/data-products/fertilizer-use-and-price.aspx#26727
. (accessed 6/11/13)