Released July 21, 2008

ST. PAUL, Minn. —- Fall fertilizer prices are very high, and will be even higher next spring. We’ve heard quoted prices for fall purchased nitrogen (N) ranging from 53 to 72 cents per pound. Fertilizer purchased next spring will cost even more—one quoted price was 94 cents per pound of N.

Soil testing is the first and best step you can take to reduce fertilizer costs this fall. Producers who are concerned about high fertilizer costs and who are not soil sampling are not really serious about saving money. Soil sampling and testing is quick and inexpensive.

Other ways to save money on fertilizer without hurting yields:

• Take nitrogen credits. Plant legumes (they fix their own N). Innoculate the seed of legumes with the proper bacteria. Mine deep N—N left over from corn, wheat and other crops will move deeper into the soil with rain. Also, take advantage of N credits from previous crops. Some legumes are worth 40 pounds of N.
• Reduce potential nutrient losses. Don’t let urea volatilize, don’t apply urea to frozen soils, and time N applications (planting or later is often the best choice).
• Use manure. If possible, apply manure on fields with lower phosphorus (P) and potassium (K) levels.
• Think through application methods. With strip till, you can reduce P and K rates since the P and K are placed in a band directly beneath the seed. Use inhibitors carefully—only in special cases will they show an advantage over standard materials.
• Get the biggest bang for your buck. Set realistic yield goals. Average five years of yield data after omitting yield values that look abnormally high or low. Then set a goal that exceeds the average by 10 to 15 percent. Also, backing off the N rate may give you the biggest bang for the buck with your first few pounds of N. The more you apply, the less each unit increases yield.

You’ll find more details in an article in Minnesota Crop eNews, published by University of Minnesota Extension.

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http://www.extension.umn.edu/extensionnews/2008/soiltest.html

Russ Severson is a crops educator with University of Minnesota Extension.

Contact: Catherine Dehdashti, U of M Extension, (612) 625-0237, ced@umn.edu