Expanded shale as a soil amendment for the Rocky Mountain region
Date
2018
Authors
Anderson, Cassandra, author
Klett, Jim, advisor
Bousselot, Jennifer, committee member
Barbarick, Ken, committee member
Journal Title
Journal ISSN
Volume Title
Abstract
Landscape soils are rarely ideal, consequently there has been abundant research about amendments for soil improvement. This research project focused on the use of compost, a long-standing successful amendment as well as expanded shale, an amendment that originated in the construction industry. Expanded shale is a shale rock that is heated to very high temperatures causing the material to fracture and create small pores. These pores make the material lighter in weight and those pores help to improve soil porosity and potentially can act to hold some levels of moisture and nutrients. The study began in October of 2015 and data was taken in the growing seasons of 2016 and 2017 from April 2016 to October 2016 and from April 2017 through September 2017. In this project six different treatments of varying levels of compost and expanded shale were incorporated into a research site at Colorado State University. The treatments were 1) 0 cm of expanded shale and 5 cm of compost (0 ES: 5 C), 2) 2.5 cm of expanded shale and 5 cm of compost (2.5 ES:5 C), 3) 5 cm of expanded shale and 5 cm of compost (5 ES:5 C), 4) 7.6 cm of expanded shale and 5 cm of compost (7.6 ES:5 C), 5) 5 cm of expanded shale only (5 ES:0 C), and 6) 7.6 cm of expanded shale only (7.6 ES:5 C). Soil moisture data was taken weekly in 2017 and physical measurements and photographic growth measurements were obtained during each growing season. A destructive harvest was performed in October and November of 2017 where top growth and roots were harvested separately and measured before being oven dried for weight analysis. Statistical analysis did not demonstrate significant differences between treatment types, however the soil amendments were not detrimental to plant growth. There is a lot of room for potential future study of expanded shale as a soil amendment for rocky mountain region soils and beyond.