Copies of author's previously published articles inserted. / Bibliography: p. 110-123. / xiii, 123 p. : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Two types of polymer, latex, a hydrophobic natural uncharged polymer, and, poly-diallyl dimethil ammonium chloride (poly-DADMAC), a hydrophilic synthetic positively charged polymer, were used as soil conditioners. Their effects on the stability of soil structure, hydrophobicity and on the growth of ryegrass were investigated. The study also monitored the rate of decomposition of latex in soil. / Thesis (Ph.D.)--University of Adelaide, Dept. of Soil Science, 1997