CHANGES IN THE ABUNDANCE OF LARGE SOIL ANIMALS AND PHYSICAL-PROPERTIES OF SOILS FOLLOWING CULTIVATION

Regular ploughing and stocking physically alter the soil. We hypothesized that these practices render soil unsuitable for large soil animals, and that the presence of large soil animals in turn enhances soil friability and infiltration of water. We found that regularly ploughed and stocked soil in the Western Australian wheatbelt was, with one exception, more compact and less permeable to water than virgin soil. Soil which had not been ploughed or stocked for seven years was as permeable to water as virgin soil, but was intermediate in compaction between virgin and cultivated soil. Virgin soils had more cavities and burrows, as well as more water-stable aggregates, than cultivated soils. Large soil animals were virtually eliminated from the regularly cultivated soils. There was little difference in the number of large soil animals between virgin soil and adjacent soil last cultivated and stocked in 1969. In summer, few large soil animals were found in any soil sampled. These findings are in agreement with the hypothesis stated above. © 1979, CSIRO. All rights reserved.