TURF RESPONSE TO COATED-UREA FERTILIZERS

摘要

Nitrogen from water-soluble urea-based fertilizers is frequently applied to turfgrasses. However, there is considerable environmental concern over water-soluble N leaching from turf. Use of coated soluble N sources has been promoted in recent years asan efficient N fertilizer strategy. Water-soluble urea may be coated to provide controlled release of N, which can extend the period of turfgrass response following fertilization. In this field study, turf response was evaluated for new and standard controlled-release N and standard slow-release N sources. Twelve urea-coated N sources were compared over 3-month periods along with IBDU, (NH_4)_2SO_4 (AS), three controlled-release urea sources + AS at a N rate of 7.5 g m~2 applied every 3-months and AS applied monthly at a N rate of 2.5 g m~2 for their effect on bermudagrass (Cynodon dacty-lonx C. transvaalensis Burt-Davvy cv. Tifgreen) grown on Hal-landale fine sand. Evaluations were based on turfgrass visual quality ratings and clipping yields. Bermudagrass visual quality and clipping yields were significantly (P < 0.01) affected by N source. However, no consistent differences were found among controlled-release N sources. Generally, a single application of controlled-release N sources did not consistently provide better turfgrass quality and greater clipping yields than a single or monthly applications of AS that provided an equivalent amount of nitrogen over the study period.