Effect of Compost Amendment On Productivity and Hydrology of a Seattle Glacial till Soil.

This project looked at the use of compost as an amendment to Alderwood series soil to increase water-holding capacity and other soil physical properties, as well as the effect of that treatment on nutrients and other constituents in runoff and productivity. At the University of Washington, seven 8 ft. x 32 ft. beds(plots) were constructed out of plywood lined with plastic and filled with Alderwood subsoil or mixtures of soil and compost. These beds were located at the College of Forest Resources Center for Urban Horticulture at the University of Washington. We measure the productivity by the biomass and total nitrogen content of the grass that grows on different treatments. Treatments with the highest amount of compost mixture are expected to be higher in productivity than control plots.