Biosolids application to no-till dryland agroecosystems

Dryland agroecosystems are generally ideal environments for recycling biosolids. However, what is the efficacy of biosolids addition to a no-till dryland management agroecosystem? From 2000 to 2010, we studied application of biosolids from the Littleton/Englewood, CO Wastewater Treatment Plant versus commercial N fertilizer in dryland no-till wheat (Triticum aestivum, L.)-fallow (WF) and wheat-corn (Zea mays, L.)-fallow (WCF) rotations at a site approximately 40 km east of Byers, CO. We tested if biosolids would produce the same yields and grain P, Zn, and Ba concentrations as an equivalent rate of N fertilizer, that biosolids-borne P, Zn, and Ba would not migrate below the 10 cm soil depth, and that biosolids application would result in the same quantity of residual NO3-N as the equivalent N fertilizer rate. Biosolids and N fertilizer produced similar wheat and corn yields; but, biosolids application resulted in smaller wheat grain Ba due to the soil formation of BaSO4. Biosolids application produced greater NO3-N concentrations than N fertilizer in the 30-60 and 60-90 cm depths for the WF rotation and all but the 5-10 and 120-150 cm depths for the WCF rotation. We concluded that biosolids application in a no-till managed dryland agroecosystem is an efficacious method of recycling this nutrient source. (C) 2012 Elsevier B.V. All rights reserved.