Changes in Soil and Bermudagrass Plant Tissue K with Rate of Application and Time.

Research was conducted on a Staser silt loam (Cumulic Hapludoll) on the Highland Rim approximately 30 miles north of Nashville (N 36° 28’ and W 86° 50’, elevation 217 m). Maintaining yield of hybrid bermudagrass (Cynodon dactylon) hay involves annual fertilization with a potassium containing fertilizer.  The high annual yields associated with this forage and removal of the hay for sale or use elsewhere on the farm quickly depletes soil test levels of potassium to the low range.  conditions.  Three years of data strongly indicate that a different management strategy is needed for efficient use of potassium fertilizer.  Potassium levels in the forage and thus removal increased with rates of fertilization but decreased at each level of fertilization as the season progressed.  No increase in soil test levels of potassium were measured at any rate of fertilization in this experiment.