Mineral Nutrition of Some Queensland Heath Plants

Australian 'heath' vegetation occurs on extremely impoverished soils of the less arid coastal areas of southern and eastern Australia. The heath of south-eastern Queensland, known as 'Wallum', in common with the other Australian heaths, shares many of the characteristics of the European heaths, consisting of stands, frequently dense, of perennial sclerophyllous shrubs and small trees, although the floristic composition is, of course, different (Coaldrake 1961). In contrast to the prolific growth of the native vegetation, the establishment and continued growth of species of agricultural importance on the Wallum soils requires the addition of at least eight nutrient elements: phosphorus, nitrogen, calcium, potassium, copper, sulphur, molybdenum and zinc (Young 1940, 1948; Mitchell & Cannon 1953; Andrew & Bryan 1955, 1958). Although there has been much speculation about the properties of heath vegetation in general which enable it to grow on infertile soils, little is known of the behaviour of the Wallum species. The present account describes an experiment in which representative Wallum species and cultivars of crop species were grown simultaneously in nutrient solution culture, and their growth responses to four major nutrients (nitrogen, phosphorus, potassium and calcium) compared.