ESTIMATING PLANT AVAILABLE NITROGEN IN BIOSOLIDS: A REVISION

In 1998, the Water Environment Research Foundation funded a project entitled “Nitrogen Management Protocols for Biosolids Beneficial Use.” One of the objectives of that project is to establish laboratory and field studies that will provide a scientifically acceptable evaluation of the plant available nitrogen (PAN) in typical biosolids. A detailed report of the first year of this project was presented at a WEFTEC Workshop at the 1999 Meetings in New Orleans. Major conclusions from the first year were:Large amounts of ammonia can volatilize from surface applied biosolids.Biosolids total PAN during the growing season is directly related to biosolids total N content.First and second year PAN can be estimated using a constant organic N mineralization percentage for a given location.