Monitor the sources, mobility and fate of nutrients and trace metals on several dairy farms with histories of long-term application of manures and sludges. Develop an integrated simulation modeling framework that comprises nutrition management, waste management and environmental transport components. Involve diverse stakeholders to ensure that research directions remain relevant and useful. Develop a shared understanding among diverse stakeholders as to the results of the research, and to disseminate results and recommendations to a wide audience. GO BACK TO TOP 4.
Conventional wisdom assumes little risk of mobility of sludge-applied trace metals to groundwater.
However, many field studies are unable to account for a substantial fraction of sludge-applied metals when the receiving soil is examined several years after application. Leaching from the soil profile is a potential mechanism for the apparent losses. We have observed substantial movement of sludge-applied metals via preferential flow paths facilitated by complexation with soluble organics irk both experimental and field systems. Rates of nutrient mineralization from land-applied sludges are also poorly defined, and over application may result in groundwater contamination. The proposed work seeks to expand, verify and model our current field and greenhouse observations of metal leaching from land-applied sludges, and to screen soil, sludge and water samples for surfactants and metabolites.