Authors: Mallory Hinton, Matthew Madsen, Raechel Hunsaker, April Hulet
Mentors: April Hulet
Insitution: Brigham Young University
Seeding plants post disturbance on rangelands is a challenge due to unique ecological and environmental conditions such as limited water availability, invasive species, soil health, and native seed supply. One of the key factors to address these challenges and have a successful seedings is understanding the relationships between soil characteristics and the plants that grow within them. Our research evaluated plant growth for seventeen grass species in two degraded rangeland soils (a mine tailings impoundment and Santaquin Wildlife Management Area) in Utah. Grasses (10 PLS/5cm 2 pot) were grown in self-watering growth trays in a complete, randomized block design with four replicates per soil type. After 21 days in the greenhouse, plant densities and aboveground biomass were collected and analyzed. Soils differed in mineral content. Iron and nitrogen were 5- and 4-fold greater in Tailings than Santaquin soil; phosphorus, magnesium, and organic matter were 5.5-, 4-, and 18-folds lower in Tailings than Santaquin soil. The average density of plants was significantly different (p < 0.0001) between the two soil types; in the Santaquin soil plant density was 5.73 plants/pot, in Tailings soil plant density was 2.20 plants/pot. No individual grass species were significantly different from each other in the Tailings soil (p = 0.51). However, individual grass species were significantly different from one another in the Santaquin soil (p = 0.05). Both Tailings and Santaquin soil types had the highest densities of slender wheatgrass (Elymus trachycaulus; 4.75 plants/pot and 8.25 plants/pot, respectively) and tall wheatgrass (Thinopyrum ponticum; 4.75 plants/pot and 10.25 plants/pot, respectively). Sandbergs bluegrass (Poa secunda) had the lowest density in both soil types (zero plants in Tailings soil and 2.50 plants/pot in Santaquin soil). To make informed decisions when selecting plant species for seed mixes, soil characteristics should be considered.