The rhizosphere effect shown by some Victorian heathland plants

Abstract

During the period July 1951 to October 1952, a study was made of the fungai population of the soil of a TVictorian heathland with reference to the rhizosphere effect exerted by five species of native plants growing there. Some 45 genera of fungi with 115 species were isolated; of these, 52 species were obtained from the free soil and the rhizosphere, 25 from the soil only, 27 from the rhizosphere, and 11 species were isolated only from dung.

During this period, the numbers of fungal propagules in the free soil, estimated by the dilution-plate technique, varied from 68,500 to 247,600 per gram of oven-dry soil; R/S ratios of 0.6–9.7 were recorded.

A study has been made of the antibiotic and cellulose-decomposing activities, and the nutritional requirements, of the mycoflora. Examination of the soil for N-fixing organisms showed that Azotobacter and acid-tolerant aerobes were absent; anaerobes were present in small numbers.