St. Augustinegrass Fertilizer Trials

ABSTRACT

Research was conducted to verify the current fertilization recommendations for St. Augustinegrass (Stenotaphrum secundatum Walt. Kuntze) lawns. Currently, a range from 100 to 300 kg nitrogen (N) ha^{? 1} per growing season is suggested, based on factors such as location in the state, desired maintenance level, soil conditions, etc. Research was conducted at the G.C. Horn Turfgrass Field Laboratory in Gainesville, FL from 2000 to 2002, utilizing medium to high management levels and at a sod farm in Bradenton, FL from 2001 and 2002, under low management conditions. Nitrogen (N) and potassium (K) treatments were arranged in a randomized complete block design with three replications in both locations. In Gainesville, best visual quality was generally obtained with medium (MN) or high nitrogen rates (HN). In Bradenton, MN, and HN rates provided best visual quality responses in 2002 and 2003, but higher rates of N were required than in Gainesville to maintain acceptable quality. This higher N requirement could be due to the longer growing season in Bradenton or to poor turfgrass growth resulting from inadequate pest control. In the absence of biotic or abiotic stresses, the highest rates of N were not necessary to maintain an acceptable quality lawn.