Millennium Fertilizer Study

Suncor initiated the Millennium (ML 22) Fertilizer Research Plot Study in 2005 to evaluate the effectiveness of fertilizer use for reclaiming and ultimately increasing rates of revegetating disturbed areas on waste overburden. The study was designed to compare the rate of coniferous and deciduous tree growth along with natural invading vegetation between fertilized and non fertilized treatment sites on subsoil capping of 100 cm of topcut material. The topcut material was taken directly below muskeg. Plots were amended with Suncor’s standard muskeg soil material (approximately 70% peat and 30% underlying mineral material by volume), seeded with barley, and planted with white spruce, trembling aspen, black current, Saskatoon berry and green alder. Treatment sites were fertilized annually. The study ran from 2005 to 2008.

Spruce and aspen seedlings increased in height with no significant difference between treatments for either species by end of study. Seedling survival decreased for both species in both treatments. Aspen seedlings had higher survival in non-fertilized plots. Browsing may have negatively impacted survival and growth. Overall, fertilizer does not appear to have affected seeding growth or survival of either tree species. Forb cover increased in the first year as they colonized reclaimed areas, then declined. A slight increase was noted in non-fertilized plots by the end, while was relatively constant in fertilized plots, but there was no significant difference between treatments. Graminoid cover was low for all years of monitoring and there was no difference between treatments. Shrub cover increased in fertilized plots, though it was less than 1% by 2008. Non-fertilized plots increased at first, then decreased. There was no significant difference between treatments. Tree cover in both treatments was low and showed similar trends over time, with no significant difference between treatments. Total living cover varied over time for both treatments; a declining trend in fertilized plots and a slight increasing trend in non-fertilized plots, showing a significant difference. Total cover (vascular + litter) showed a similar trend to total living cover but the difference was not significant.