I occasionally write for another blog on my advisor’s website and thought some readers here may be interested in a recent post– Lab Methods for Soil Testing. I broke down some common methods for measuring soil test phosphorous and potassium. These methods can be important when you’re comparing your soil test values to the critical level for a given nutrient, soil texture, and state. If your soil test values were derived using a different lab method than the method used by researchers to generate the critical level in your region, you may need to convert your values in order to make accurate fertilizer recommendations. You can learn all about that process on the Cool Bean Blog!
The data I used for the quick regression in the Cool Bean blog post is from an on-farm fertilizer trial that I soil sampled last November. It was just after the fall time change, so the sun started setting while I was sampling the last replication. The soil samples were analyzed using both Bray and Mehlich extraction techniques by an outside lab, and I’ll be using the data as part of a larger project to evaluate potassium fertilizer recommendations. I also took some videos of the planning and sampling process as part of a winter video series for OSU Extension (I’ll be sure to share the link when it’s publicly available). It’s always great when a single day in the field can be useful for long-term research and a few in-season Extension materials too!