Interim Report of Soil Research Related to Revegetation of the Oil Sands Area

Monitoring was continued at instrumented sites which were selected in spring 1976, at Mildred Lake, Supertest Hill, the GCOS dike, and near Richardson Tower. Because of budget limitations, sites at Richardson were only monitored occasionally. However, information was obtained at a number of temporary 'outlying sites', which showed that conditions at the instrumented sites are fairly representative of those under similar vegetation in the surrounding area. Special emphasis in 1977, was placed on obtaining detailed information on moisture tensions using thermocouple psychrometers, and in acquiring accurate information on changes in moisture distribution during spring thaw. Growth of grasses and legumes in tailings sand, and the effect of adding materials such as peat and glacial till to tailings sand, were studied using lysimeters both indoors and in the field, and by establishing small plots, all of which were instrumented for gathering of physical and chemical information. Aspects of nutrient cycling such as nutrient inputs and outputs at forest sites, nitrogen mineralization and immobilization, retention of nitrogen by soil mixes, and decomposition of plant materials, were investigated with 15N and 14C. Laboratory studies were carried out on nitrogen and carbon cycling in tailings sand and two overburden materials. Much interpretation of information gathered over the year is still to be done and will be included in the next report.