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.
(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)