Convergence Research Seminar Series, Dr. Ippolito (Ohio State University)

Abstract: Biosolids land application research began shortly after the enactment of the Clean Water Act in 1972; research continues today.  This presentation quickly summarizes 45 years of biosolids land application research in the western US, focusing attention on nutrient recovery/use from biosolids, environmental chemistry, agriculture, and soil science.  Pastureland research suggested that sewage effluent could be land-applied, benefitting plant growth and polishing water prior to reaching waterbodies.  Biosolids application to forest wildfire areas led to greater plant establishment, soil microbial activity/nutrient turnover, and reduced nutrient/heavy metals in runoff to below drinking water standards.  Forty years of dryland agroecosystem research has identified: a) biosolids nitrogen (N) fertilizer equivalency; b) first year N mineralization rates needed; c) negated the biosolids-borne heavy metal “time bomb” theory; d) farmer economic return is increased; e) biosolids-borne proteins are labile C/N sources; f) heavy metals tracking in soils/plants – soil concentrations will not lead to groundwater…