Bibliography: p. 283-313. / xxxii, 313 p. : ill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Two systems of dryland cropping, one conventional and one conservation, were studied on the same farm over a period of 10 and 14 years respectively. The conventional cropping system was based on cultivated fallow which served to manage and conserve water, nitrified organic matter and controlled weeds. Stubble was burnt prior to cultivation for the fallow phase, with pasture and cropping phases rotated. The conservation farming system was based on the absence of soil tillage, stubble retention, rotation of a variety of crops and chemical control of weeds. Water conservation was achieved through increased infiltration by improved soil structure, avoidance of compaction, reduced water runoff and reduced evaporation by stubble retention. Overall, the conventional farming system was proven to be unsustainable. The conservation system was sustainable in terms of productivity, profitability and effect on the environmental resources of soil and water. The growing of sorghum as a summer grass in the Wimmera was also found to be an opportunity for improving productivity, profitability and sustainability by controlling winter weeds. / Thesis (Ph.D.)--University of Adelaide, Dept. of Agronomy and Farming Systems, 1998

Bibliography: p. 283-313. Two systems of dryland cropping, one conventional and one conservation, were studied on the same farm over a period of 10 and 14 years respectively. The conventional cropping system was based on cultivated fallow which served to manage and conserve water, nitrified organic matter and controlled weeds. Stubble was burnt prior to cultivation for the fallow phase, with pasture and cropping phases rotated. The conservation farming system was based on the absence of soil tillage, stubble retention, rotation of a variety of crops and chemical control of weeds. Water conservation was achieved through increased infiltration by improved soil structure, avoidance of compaction, reduced water runoff and reduced evaporation by stubble retention. Overall, the conventional farming system was proven to be unsustainable. The conservation system was sustainable in terms of productivity, profitability and effect on the environmental resources of soil and water. The growing of sorghum as a summer grass in the Wimmera was also found to be an opportunity for improving productivity, profitability and sustainability by controlling winter weeds.