The frozen ground with variable snow cover can lead to some retailers and their farmer customers to choose to take the time to spread delayed fall potassium applications, according to an article by PennState Extension. The frozen ground provides ideal conditions for reduced compaction from heavy fertilizer equipment. Winter can be a good time to spread lime as well as potash on fields where the potential for runoff is minimal, such as relatively flat fields with some residue cover. Runoff of lime or potassium (K) is not an environmental hazard, but rather is an economic loss of fertility inputs.
Wintertime applications of phosphorus (P) containing fertilizers, however, should be avoided when possible because of the negative environmental effects of P runoff. Be cautious of wintertime applications in excessive wind, which can disrupt the spread pattern for broadcast spreaders.
Application rates of lime and potash are best determined from a recent soil test. The opportunity for wintertime fertilizer spreading is a great example of why soil testing in the fall can be advantageous. If you don’t have a recent soil test, you can use expected crop removal rates for the upcoming crops in the rotation as a guideline for potash applications.