The soil potassium (K) test methodology is under increased evaluation due to the soil sample drying effect, temporal variations of test results and inconsistent crop response to applied K fertilizers. Ten on-farm trials were conducted in 2014 in eastern North Dakota to determine the corn response to different K-fertilizer rates and to assess the variation of soil K test levels between air-dried (KDry) and field moist (KMoist) soil samples during the corn growing season. Significant differences were observe d between KDry and KMoist soil K test results. The ratio of KDry/KMoist showed high correlation with cation exchange capacity (r = , p | Evaluation of Soil Potassium Test to Improve Fertilizer Recommendations for Corn
