After buying a high-yielding racehorse hybrid, you wouldn’t head to the field before checking your planter’s settings. It makes sound economic and agronomic sense to stick with the same logic when it comes to your fertility program.
One of the best ways to manage input costs is to do all you can to maximize returns. And although fall fertilizer applications offer several advantages, such as reduced compaction, spreading your workload and lower costs, you can take several steps to help ensure you realize the greatest value possible from those applications.
The University of Wisconsin Soil Science Department offers several steps to help maximize fertilizer returns.1 Soil testing tops the list and is an important factor affecting several steps on the Wisconsin Extension list. Other factors to keep in mind this fall include:
- Lime adequately.
- Use right rate, according to soil test.
- Take nutrient credits — from manure applications, for example.
- Maximize efficiency and avoid losses.
- Avoid unnecessary additions — consider the law of diminishing returns.
Fall is the best time to apply lime. The timing allows it to neutralize soil acidity before crop growth begins.2 Fall also is a good time to apply phosphorus (P) and potassium (K). In fact, research has shown no obvious difference between spring and fall applications for P and K.3
Fall-applied nitrogen (N) requires special attention. Iowa State University Extension specialists offer these suggestions for fall N applications:
- Use only anhydrous ammonia.
- Apply in late fall after soils cool to 50 degrees (at a 4-inch depth) and are trending cooler (the colder the better).
- Consider a nitrification inhibitor to further slow nitrification.
- Avoid fall application to soils that are more prone to wetness or leaching (poorly or excessively drained soils).4
Soil condition — moisture, texture and type — impact anhydrous retention and movement in the soil.4 It’s important to adjust application equipment or wait until soil conditions improve to avoid losses. If your application equipment could use an upgrade, talk with your Case IH dealer about our full line of fertilizer application equipment. Efficient, timely application, along with proper placement, can help you realize the best returns possible from your fall applications.
RESOURCES
1Laboski C. Soil Sampling, Fertilizer Recommendations, and Economics of Fertilization. University of Wisconsin website. http://www.soils.wisc.edu/extension/materials/Sampling_Fert_Recs_Econ.pdf. Accessed October 18, 2015.
2Larson E, Oldham L. Corn Fertilization. Mississippi State University Extension website. http://msucares.com/pubs/infosheets/is0864.pdf. Accessed October 18, 2015.
3Sawyer J, Mallarino A. Getting Ready for Fall Fertilization. Iowa State University Extension website. http://crops.extension.iastate.edu/cropnews/2009/09/getting-ready-fall-fertilization. Accessed October 18, 2015.
4Sawyer J. Fertilizer Nitrogen Application this Fall. Iowa State University Extension website. http://crops.extension.iastate.edu/cropnews/2015/10/fertilizer-nitrogen-application-fall. Accessed October 18, 2015.
