Effect of Fertilizer Source on Nitrate Leaching and St. Augustinegrass Turfgrass Quality

Abstract

As a result of the coexistence of turfgrass and ornamentals in traditional landscapes, it is often impractical to separate fertilization and irrigation management among species. Furthermore, limited information is available on effects of turfgrass fertilizer on ornamental plants and vice versa. This research studied effects of two quick-release fertilizers (QRF) and one slow-release fertilizer (SRF) on quality and growth of turfgrass and ornamental plants and nutrient leaching. ‘Floratam’ St. Augustinegrass ( Stenotaphrum secundatum Walt. Kuntze) was compared with a mix of common Florida ornamentals, including canna ( Canna generalis L.H. Bailey), nandina ( Nandina domestica Thunb.), ligustrum ( Ligustrum japonicum Thunb.), and allamanda ( Allamanda cathartica L.). All plants were grown in 300-L plastic pots in Arredondo fine sand. Less nitrate (NO 3 − ) was leached from turfgrass than from ornamentals and more NO 3 − leached from QRF 16N–1.7P–6.6K than from SRF 8N–1.7P–9.9K. Quick-release fertilizers produced higher plant quality. This controlled environment research provides preliminary data on which in situ research may be modeled. Further research is required to verify how nutrient release rate affects turfgrass and ornamental quality and nitrate leaching in an urban landscape.