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Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Soil Science,1993

The use of soil cement as a growth medium was examined in this study. During the monitoring, green soil cement revealed diverse ecological values. The survival rates of plants in each soil conditions were higher than 80%,which was very promising. Furthermore, the survival rates dropped when the soil density reached95%, which means soil density might influence the survival rate of plant. Plant growth rates in sandy soil were higher than that in soil cement. In particular, low soil density facilitated plant growth in sandy soil, whereas density effect was not clear to plant growth performance in soil cement. Experiments were undertaken to study the soil-water characteristics of sandy soil and soil cement in field and laboratory condition. The influence of vegetation and material density on the development of negative pore water pressure (PWP) and degree of saturation (Sr) in the studied materials was investigated. The field planting experiments proved a promising survival rate of Schefflera heptaphylla in both types of materials while sandy soil promoted better growth of the seedlings than the soil cement. From the field study, PWP and Sr of sandy soil responded noticeably and promptly to natural drying and wetting cycles. However, the responses in soil cement were relatively mild. When subjected to the same drying-wetting cycles, PWP responded more slowly and to a smaller magnitude compared with that of soil cement. In addition, Sr changed little in soil cement. An increase in the density of the sandy soil promoted rapid development of negative PWP, while an opposite trend was observed for soil cement. Attempts have been made to explain the observations from the perspectives of material permeability and change in water content during a drying period in both soil types. Furthermore, in sandy soil, the development of PWP (with a measurement limit of -90 kPa) was minimally affected by the presence of vegetation, while vegetation noticeably helped the development of negative PWP in the soil cement. Bounds of the soil-water characteristic curve of the studied materials were presented based on estimates from the drying and wetting scanning curves derived from the field monitoring. A complementary laboratory study was carried out in an environmental chamber with controllable temperature and humidity. Monitoring results from the laboratory agreed well with that obtained from the field. / published_or_final_version / Civil Engineering / Master / Master of Philosophy

No description available.

Water balance calculations were conducted for data obtained from a soil moisture characteristic to demonstrate the effect of different subsurface drain depths on the extent of droughtiness of a sandy soil. / Laboratory experiments were conducted on samples of sandy soils of the St. Lawrence lowlands to determine pertinent physical and soil-water properties. These properties were used, together with published crop data, to determine the effect of different subsurface drain depths on the quantity of available water in the soils studied. / Empirical relationships were derived among some of the properties measured, with the objective of enabling future drainage planners to make preliminary assessments of the likelihood of the occurrence of excessive drainage in a particular soil. / Based on information gained from this study, subsurface drainage-problem cases, representing conditions similar to those existing in the fields studied, were analysed and designs or design improvements were suggested for minimising the problem exemplified in each case.

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona, 1989. / Includes bibliographical references (leaves 114-118).

Thesis (M. Ag. Sc.)--University of Adelaide, 1972. / Includes bibliographical references (p. 219-237).

Thesis (Ph.D.)--University of Adelaide, Department of Soil Science,1993.