Coastal Bermudagrass Response to Applications of P and K as Related to P and K Levels in the Soil
1966
Jordan, C. W. | Evans, C. E. | Rouse, R. D.
The response of Coastal bermudagrass (Cynodon dactylon L. Pers.) to applications of P and K as related to P and K levels in the loamy sand and sandy loam soils of the Lakeland-Norfolk series was studied from 1959 to 1963. The annual rate of 240 lb N/acre was applied in four applications. Effect of treatment on yield, plant content of P, K, Ca, and Mg, and change in soil test values of the surface 24 inches were determined each year. The relationships between yield and soil test P and K were described by curves calculated with a modification of the Mitscherlich equation to the form log (A − y) = log A − bᶜ using data for initial and final years. The curves obtained showed yield response to P at soil test values < 25 ppm P and yield response to K at soil test values < 40 ppm K. Chemical analysis of samples from the surface 2 inches of soil was representative of the P and K fertility. Plant contents above 0.16% P and 1.0% K were adequate for maximum production. A fungal disease apparently associated with K deficiency was observed on plots receiving no K at 10 of the 18 locations in 1961 and subsequent years.
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