The Relationship Between Some Nitrogen Fertilizer Sources, Rates, Application Frequencies, and Quality of ‘Tïfgreen’ Bermudagrass1

Abstract

Effects of 16 nitrogen treatments were compared in 1974, 1975 and 1976 on a United States Golf Association (USGA) golf green planted with ‘Tifgreen’ Bermudagrass (Cynodon dactylon (L.) Pers × C. transvaalensis). Activated sewage sludge (Milorganite) was superior to ammonium nitrate and ureaformaldehyde (Uramite) at most rates and application frequencies. The best quality (by panel evaluation) turfgrass resulted from 1.80 kg per 92.9 m2 of Milorganite N applied monthly (May to November) or bimonthly applications of 5.40 kg. Biweekly applications of 0.45 or 0.90 kg of ammonium nitrate N ranked next, but monthly applications of 0.45 to 1.35 kg failed to provide acceptable turfgrass quality. Ureaformaldehyde N at monthly rates from 0.45 to 1.80 kg was inferior to other sources at the same rates and application frequencies. Foliar concentrations of N, P, K, Cu and Zn above critical levels were associated with increased quality and yield. Tissue Mg, S, Fe and Mn content had no influence on turf quality or yield. Foliage micronutrient levels were generally higher than previously reported by other workers.