By Madeline Desjardins, 2022-2025 FFAR Fellow
at Washington State University
Like most people, I once spent virtually no time thinking about the content of toilets and where those contents went after a flush. This all changed when I began my Ph.D. work in Dr. Deirdre Griffin LaHue’s Soil Health Lab at Washington State University. With funding from the FFAR Fellows Program and the King County Wastewater Treatment Division, my graduate research focuses on how biosolid byproducts from our waste stream can improve soil health and support sustainable agricultural production.
My research focuses on how biosolids influence the physical, biological, and chemical soil health properties of semi-arid dryland grain systems, and whether biosolids can help growers establish cover crops in these systems. The geography of this research is in dryland systems in Central Washington. These systems face some specific challenges related to water availability that can severely limit crop yields. Annual precipitation in this area is low (~10 inches of precipitation a year), and these systems rely solely on precipitation to meet the water needs of the crop (this means they are completely unirrigated).