Monday, November 13, 2006 - 3:45 PM

Long-Term Water Treatment Residuals-Biosolids Co-Application Affects Rangeland Soils and Plants.

Jim Ippolito, Kenneth Barbarick, and Mark Paschke. Colorado State Univ, Dept of Soil & Crop Sciences, 200 W Lake St, Fort Collins, CO 80523

The city of Fort Collins, Colorado owns 10,390 ha of semi-arid rangeland for use in recycling municipal wastes via land application.  In 1991, a study was initiated to determine the potential short-term impacts of water treatment residuals-biosolids co-application on soils and vegetation.  Treatments consisted of 10 Mg biosolids ha-1 co-applied with 5, 10, and 21 Mg water treatment residuals ha-1 to 15 x 15 m plots.  All treatments were replicated four times.  In October 2002, the plots were divided in half with one half of each plot receiving rates identical to the 1991 application.  Soils data was collected in June 2004 and June 2005, and vegetation data was in June 2005 to access the short-term impacts of a repeated co-application and the long-term impacts of a single application on ecosystem dynamics.  Results will be discussed.