Author(s): Joanna Pincock, Mallory Hinton
Mentor(s): April Hulet, Matt Madsen
Institution BYU
Degraded rangeland soils, like those found at mining sites, often exhibit diminished fertility and altered physical properties, leading to decreased plant diversity, unstable soil structure, lower water infiltration, and a decline in ecosystem resilience. By establishing forbs in these areas, we can address these challenges while also supporting a broader range of wildlife and pollinators. This study evaluated the plant production of 20 forb species on three soils (mine tailings impoundment, mine rock dump, and degraded rangeland). Forb seeds were pretreated with either an oxygenated water bath, oxygenated gibberellic acid (GA3) water bath, cold-moist stratification, or no treatment to determine the best methodologies to overcome seed dormancy requirements and enhance field germination and establishment. For seeds with no pretreatment, significant differences (p < 0.05) in forb density were observed across all soil types: mine tailings had 0.2 plants per 5 cm², mine rock dump had 2.8 plants per 5 cm², and degraded rangeland soil had 4.5 plants per 5 cm². After 21 days of growth, aboveground biomass per square meter was highest in degraded rangeland soils (12.1 g), followed by mine rock dump (5.9 g), and lowest in mine tailings impoundment (0.4 g). Among the species studied, Achillea millefolium, Medicago sativa, Onobrychis viciifolia, and Sanguisorba minor exhibited highest density and biomass across all soil types. Future research will continue to examine treatments to increase plant production both in greenhouse and field trials.