Nitrogen/Potassium fertilization ratios for bermudagrass turf

Turfgrass fertilizers often contain approximately one-half as much potassiu m (K) as nitrogen (N), on a weight basis. Since K fertilization has been sh own to be very beneficial for turfgrass appearance and growth, higher rates of K fertilization, relative to N, have been suggested. The effect of K/N fertilization ratios on 'Tifgreen' bermudagrass [Cynodon dactylon (L.) Pers . x C. transvaalensis Burtt-Davy] growth and quality was studied over a 3-y r period in south Florida for three rates of N fertilization. Severe K defi ciencies were observed in the absence of K fertilization. However, increasi ng K fertilization beyond a K/N fertilization ratio of 0.5 to 1 had virtual ly no effect on turfgrass appearance, growth, on resistance to bermudagrass decline, or on root weight. Increasing K fertilization relative to N ferti lization did not provide commensurate increases in tissue K.