W Crop Performance Testing Information Available 

        The 2007 University of Wisconsin performance information for corn, soybean, alfalfa, grasses, and small grains is now available on the Internet.  To obtain the appropriate links for each crop, go to the Fond du Lac County Agronomy web site at:  http://www.uwex.edu/ces/crops/timelyPI.htm 

        The information can be viewed, printed or downloaded as a computer spreadsheet file.  For those familiar with spreadsheets, this is a handy format for sorting the data by whatever performance parameter you desire (yield, location, year, etc.).   

        Remember the important rules of thumb when making hybrid/variety selections: 

1)  Make selections based on yield information from MULTIPLE years and locations.  Purchasing seed based on results from a single location and year is very risky. 

2)  Gather as much information as possible.  Use the UW performance trial data in conjunction with local “on-farm” strip trials or seed company trials.

3)  Make selections based on more than one performance criteria.  In other words, don’t purchase a hybrid or variety only because it demonstrates high yield or is tolerant to a specific herbicide or insect pest. 

4)  Make selections based on consistent performance.  There is no “best” hybrid or variety.  Purchase those that rank at or near the top across a range of environments and locations. 

It’s not just nitrogen that’s high priced 

        Phosphorus(P) and potassium(K) fertilizers will also come at a premium in 2008.  MAP, DAP, and potash (0-0-60) prices are increasing right along with N fertilizer sources.  The best we can do to make the most of our P and K investment is to not over apply.  Of course this can only be determined if you have a reasonably up-to-date set of soil tests.  As with N, prudent use of manure and taking appropriate P and K credits will go a long way in reducing the fertilizer bill.   

        Carrie Laboski, UW Extension Soil Scientist, recommends the following guidelines to prioritize fertilizer applications in 2008:

1.       Use a current soil test

2.       Make sure soil pH is adequate for the rotation

3.       Credit nutrients in manure and legumes

4.       Apply fertilizer first to lowest testing fields

5.       Apply some fertilizer to all fields likely to respond

6.       Defer applications on soils testing high, very high, or excessively high, but be careful with high removal crops such as alfalfa and corn silage.
 

Manipulated Manure - - impacts on nitrogen 

        Farms dealing with large quantities of manure often manipulate it either by separating the solids from the liquids or running the manure through an anaerobic digester.  Sometimes both processes are done.  Although there is usually little change in total nutrient content, there is often a change in the form and availability of nitrogen (N) in manipulated manure.  Separation of the solid manure fraction from the liquid is not a “perfect” process.  That is, generally only the larger particles are separated and the liquid is far from drinking quality.  Most of the N and phosphorus remain in the smaller particles of the liquid fraction; however, the total carbon (C) content of the liquid fraction is reduced significantly.  This decreases the C:N ratio of the liquid fraction.  By doing so, the N is made more readily available. 

        Anaerobic digestion has a similar impact on manure N.  The carbon is converted to biogas.  Further, organic N is mineralized to ammonium-N, a process that naturally occurs once undigested manure is incorporated into the soil.  The loss of carbon, which lowers the C:N ratio, and the increase in ammonium-N both contribute to higher N availability in digested manure. 

        So what does all of this mean?  If manure is manipulated then forget about “book” values for nutrient content and availability.  You have to test, and test often! Further, testing for ammonium-N, nitrate-N, and C:N ratio is helpful to determine the exact first year availability.  These tests need to be requested from the lab.  There is currently on-going research to further document differences in nutrient content and form from manipulated manure.    

Fire-up those grain aeration fans 

        Now that our winter has arrived, don’t neglect a valuable grain crop that’s tucked away in the bin.  It’s normally recommended that the grain temperature be kept within 20 degrees of the outside air temperature.  This means stored grain will need to be cooled to a temperature of 20 to 30 degrees for safe winter storage.  The best way to do this is with aeration fans. If grain is not aerated in the fall, air near the bin wall cools and migrates toward the bottom of the bin.  This creates a convection current.  The air then rises up through the warm grain and picks-up moisture in the form of water vapor.  This air continues to move toward cooler grain near the top surface where the moisture condenses and causes spoilage.  The most common location of wet or spoiled grain is at the top-center of the bin or on the cold north wall.  The length of time needed to cool grain will depend on the airflow per bushel delivered by the fan.  This varies with each system.