Read the fine print on the research

I ran across this research study on potassium and tillage.  The 2 year study concluded that tillage did not affect the corn yields.  They did have a double variable in that they as tested timing and application of potassium.  There was a yield response to potassium.  Does this mean you should always apply potassium?  By no means.  Look At he soil test levels.  Potassium was low in this study to start with. I would expect a response to the fertilizer.  This is a simple test.  There are far more complex issues.  Soil amendments are not one size fits all.  The first step in making decisions related to your soil is to get it tested.  Then you can decide if you need sulfur, gypsum,micro-nutrients, or any of the other amendments that are popular at the time.