Economics of nitrogen application this fall Nitrogen prices have risen sharply since last fall and the outlook is for even higher prices a year from now. Why? Natural gas is the most costly component in the manufacture of nitrogen fertilizer. The Fertilizer Institute estimates natural gas makes up 70-80 percent of the cost of producing ammonia, the source of all nitrogen fertilizers. The price of natural gas is close to 20 percent higher than a year ago and is expected to go higher by spring. This fall, anhydrous ammonia is selling for approximately 21 cents per pound, up about a nickel from last fall. Given this scenario, growers will naturally watch nitrogen rates closely and only apply what they feel their corn crop needs for optimum growth. The U of M has done extensive research in the area of nitrogen. Research has found that for corn yield goals of 150-174 bushels per acre, the nitrogen recommendation is 120 pounds per acre for medium to high organic matter soils. The nitrogen rate increases to 140 pounds per acre for a yield of 175-199 bushels per acre on medium to high organic matter soils. Both recommendations are based on corn following soybeans in the crop rotation. Remember the following best management practices when setting nitrogen rates: o Set realistic yield goals. o Adjust nitrogen rates for soil organic matter content, previous crop, and manure applications. o Use a soil nitrate test in western Minnesota to check on nitrogen reserves in the soil. o Credit second year nitrogen contributions from alfalfa and manure. o Utilize nitrogen, to the fullest extent, in manure. o Time the application of nitrogen for maximum efficiency. We can normally count on soil temperatures to stay below 50 degrees in the Meeker County area sometime between Oct. 20-25. Applying nitrogen before these dates is risky because of the conversion of nitrogen from ammonium to nitrate. More on ladybugs I wrote an article a few weeks ago on ladybugs. I have had lots of questions since then so I thought I would repeat a few key points. The Asian ladybugs could be found in large numbers late this summer, especially in soybean fields. They feed on soybean aphid, a relatively new insect pest of soybean growers. Unfortunately, as summer wears down, soybean aphids head for their over-wintering host, the buckthorn, and Asian ladybugs begin looking for a warm place to spend the winter. The past few years, many Asian ladybugs have crept into our homes. A few come out of hiding nearly every day during the winter months in our homes. They are mostly harmless but certainly a nuisance indoors. Whatever can be done to seal up homes now for the winter will help reduce their presence. Insecticides such as deltamethrin, bifenthrin, cyflu-thrin, and permethrin can be sprayed on siding and the house foundation. Repeated applications should be made during the fall. The migration into homes continues until early November. They seem to congregate on the south and west side of the home so be sure these areas are sprayed. We also see ladybug migrations peak when warm weather follows cold weather. Once inside, about all that can be done is to vacuum up ladybugs when they congregate in sunny windows. Tree seedlings for sale The Minnesota Department of Natural Resources has tree seedlings available at very reasonable prices. White spruce are available at 30 cents per tree while 8-inch ash costs 52 cents. The minimum order is 500 total trees and may be broken down into increments of 100 of each species. Orders for 2004 continue until early spring or until the supply is gone. Trees will be delivered to drop-off points around the state in early spring. For more information, stop by and ask for the Minnesota State Forest Nurseries Tree Order Form.
