An on-farm, small plot study conducted in 1996, on a Crider soil in Larue County, Kentucky, resulted in unanticipated wide variability of soil test potassium (STK) values between spring and fall sampling. Because of this, the small plots were sampled monthly over a period of time with the objective of determining if such variability in STK values was real.
Wells, Kenneth L.; Dollarhide, James E.; and Sikora, Frank J., "Small Scale Temporal and Spatial Variability of Potassium Soil Test Values On A Crider Soil" (2000). Agronomy Notes. 7.