Irrigated public open spaces

摘要

Lawn irrigation trials were used to examine the effects of frequency and duration of watering, and fertiliser application, on local lawn grass species in Darwin, NT. The growth of local turf species was monitored with a view to suggesting best active irrigation practice for gardens and ovals in the greater Darwin and Palmerston region (a wet-dry tropical climate classification) to ensure reduced, and efficient, consumption of water. Six test plots on a well-established local public lawn were established, and irrigation and fertiliser application treatments were applied. A contour survey was performed to measure slope, and to help quantify run-off losses; species identification was undertaken to establish existing conditions. Site investigation identified the soil colour, texture, saturated hydraulic conductivity, moisture content, bulk density, particle size distribution, and root zone depth at the plots. A local weather station was established to measure rainfall, temperature, relative humidity, solar radiation, wind speed, and evapotranspiration losses. Soil nutrient testing was performed to assay the chemical composition of the sub-surface soils in the rhizosphere. Grass growth and biomass development over time were used to find a horticultural regime best-suited to the irrigation of Darwin and Palmerston’s public, open, green spaces. The trial followed current principles of good irrigation practice and used an effective monitoring strategy to examine the growth rate of the grass (various species) throughout the dry season of 2016. The results provide valuable recommendations and supporting information enabling improved irrigation practice in the wet-dry tropics, with implications that go beyond water efficiency.