EFFECTS OF DIFFERENT NITROGEN SOURCES ON TURF QUALITY AND PLANTS GROWTH OF SOME WARM-SEASON TURFGRASSES

This research was conducted to determine the effects of different nitrogen sources and rates on some warm-season turfgrasses under Mediterranean-type climate conditions in 2017-2018. The experimental design was a split-split plot with design with three replicates; turfgrass species as the main plot, nitrogen sources as the subplots, and nitrogen doses as the sub subplots. The main plots consist of four nitrogen sources: two slow-release fertilizers, one organomineral fertilizer, and one sewage sludge. Subplots consist of three warm-season turfgrass species; zoysiagrass (Zoysia japonica Steud.), hybrid Bermudagrass (Cynodon transvaalensis x Cynodon dactylon), seashore paspalum (Paspalum vaginatum Sw.), and one cool-season turfgrass species, tall fescue (Festuca arundinacea Schreb.). The nitrogen doses were as follows; 0.0, 2.0, 3.0 and 4.0 g m-2. Turf color and quality were evaluated visually monthly. Also, clipping weight is determined. According to the result, slow-release and organomineral fertilizers can be assessable as N sources that will meet the nutritional needs of the turfgrasses. Zoysiagrass and seashore paspalum showed almost equivalent scores and gave sufficiently dark turf color and quality. Turfgrass should be fertilized at least with 3.0 g m−2 N to provide acceptable turf color and quality.