Page-Dumroese, D.S., M.R. Ott, D.G. Strawn, and J.M. Tirocke.
Applied Engineering in Agriculture 34(1):43-55(2018)

The U.S. Department of Agriculture, Forest Service, in cooperation with the City of Bend, Oregon, initiated a mine tailing reclamation project in the Umatilla National Forest in northeastern Oregon to determine the benefits of surface-applied organic amendments. Researchers established a field study using organic amendments applied to gold dredgings capped with 10 cm of loam and showing little evidence of regeneration. Study plot applications consisted of biochar, biosolids, or wood chips singly or in combination. Each plot was divided in half; one half was seeded with native grasses and forbs, and the other was planted with a combination of California brome and Jepson's blue wild rye. After two growing seasons, no significant differences were observed in plant cover between the planted or seeded plots, but soil properties were significantly altered by individual treatments. Combination treatments improved nutrient availability and soil moisture and grew up to twice as much plant cover as the control plots. https://www.fs.fed.us/rm/pubs_journals/2018/rmrs_2018_page_dumroese_d001.pdf