• Ren, Yaping
  Master of Science (in Forestry) The Graduate School University of Maine
  

Papermill sludge ash is being applied to forest land as a forest soil amendment in programs exploring ways to manage this mill residual. Monitoring of soil physical, chemical, and biological properties affected by the alkali materials is needed. A field study combined with lab monitoring was conducted to assess the influence of various sludge ash application rates on forest soil microbial populations and activities during the 1993 growing season (spring-fall). The research site was established in the Heald Ponds, western Maine, United States. The sludge ash was applied in early September, 1992 at rates of 0, 3, 6, and 9 ton CaCO3 equivalent per acre. Soil from an adjacent, unharvested hardwood stand was also analyzed. Forest floor soil samples were assayed at 1, 8, 9,10, 11, 12, and 13 months after the sludge ash application.