RT Journal Article SR Electronic T1 Above and Belowground Growth of Corymbia maculata in a Constructed Soil: The Effect of Profile Design and Organic Amendment JF Arboriculture & Urban Forestry (AUF) FD International Society of Arboriculture SP 11 OP 17 DO 10.48044/jauf.2010.002 VO 36 IS 1 A1 Karen Smith A1 Peter May A1 Robert White YR 2010 UL http://auf.isa-arbor.com/content/36/1/11.abstract AB Spotted gum (Corymbia maculata (Hook.) K.D. Hill & L.A.S. Johnson), a common street tree in southern Australian cities, was used to assess growth responses to variations in profile design and organic amendment of constructed soils. Aboveground growth responses were total stem dry weight and foliar nutrient content. The belowground response was root length density. Soil profiles were constructed of sand, amended with either coir fiber, composted biosolids or composted green waste, at rates of 0, 5, 10 or 20% by volume. The profiles were either layered, with a 150 mm (6 in) organic-amended surface layer, or uniform, with amendment of the entire profile. A single fertilizer treatment was applied to all profiles. Shoot dry weight was only affected by organic matter type with the greatest growth in sand amended with composted biosolids. Foliage P and K content were affected by amendment but foliage N was not. Profile design affected root length density and distribution. Trees in uniform profiles had greater root length density, and a more uniform distribution of roots, especially with compost amendments. Above- and belowground growth increases are thought to be due to increased nutrient status resulting from organic matter mineralization.