Nitrogen mobility in biosolid-amended glaciated soil

The potential leaching and availability of nitrogen in biosolids and biosol id-amended glaciated soil were investigated using mineralization and column studies. Aerobic and anaerobic mineralization studies were conducted to as sess nitrogen mineralization potential from biosolid-amended glaciated soil s and estimate long- and short-term mineralization rates of products. Semic ontinuous column studies were conducted to assess the leachability of nitro gen from biosolid-amended soil under simulated unsaturated soil conditions. This study used a Paxton soil because its characteristics are typical of g laciated soil found in New England. Three types of biosolids, which are rep resentative of biosolids currently available in Connecticut, were evaluated : composted biosolids (compost), cement kiln dust stabilized (CKD) biosolid s, and heat-dried biosolids (pellet). Results indicate that. the pellet pro duct had the greatest mineralization potential (based on unmixed biosolids) at 5 317 mg N/kg, followed by compost (324 mg N/kg) and CKD biosolids (58 mg N/kg). Nitrogen mineralized for the anaerobic test (mixed with soil) var ied from 56 to 90% of the total nitrogen and for the aerobic test varied fr om 19 to 57%. The CKD biosolids percolate consisted primarily of nitrate an d nitrite, whereas the predominant nitrogen species found in compost and pe llet biosolids percolate was ammonium. Results suggest that one-time applic ation of biosolids at agronomic or Liming rates (whichever is limiting) wil l cause minimal effects to groundwater.