Soils IssuesIMPACT OF COAL COMBUSTION PRODUCT AMENDMENTS ON SOIL QUALITY: I. MOBILIZATION OF SOIL ORGANIC NITROGENStuczynski, T. I.1,2; McCarty, G. W.1; Wright, R. J.1Author Information 1Environmental Chemistry Laboratory, USDA-ARS, Beltsville, MD. Dr. McCarty is corresponding author. E-mail: [email protected] 2Institute of Soil Science and Plant Cultivation, Pulawy, Poland. Received March 23, 1998; accepted Aug. 3, 1998. Soil Science: December 1998 - Volume 163 - Issue 12 - p 952-959 Buy Abstract There is growing interest in the use of coal combustion products (fly ash and bed ash) at agronomic rates, based on the liming requirements of agricultural soils, and at higher rates in technologies for reclamation of degraded lands. There is concern, however, that excessive or other improper use may have a negative impact on soil quality and the environment. To determine the influence of potentially excessive rates of coal combustion products on the fate of soil organic N and impacts on soil quality, we studied the effects of fly ash and bed ash applied at rates of 0, 20, 40, and 80 g kg−1 soil on the content of organic N in soils incubated for 10, 25, or 60 days. Studies comparing the influence of these products on the organic N content of the soil showed that although applications of fly ash had little influence on the fate of this N, application of bed ash caused substantial decreases in the total N content of water-extracted soil through the mobilization of organic N. Measurements of the changes in acid hydrolyzable N components of organic matter in soils treated with high rates of bed ash showed that within the first 10 days of incubation, losses of N in the forms of amino sugars, amino acids, and hydrolyzable NH + [over] 4 could account largely for losses of total N in bed ash-amended soils. Decreases in the amino acid content of soil organic matter accounted for most of these losses, and such decreases were directly related to increases in soil pH caused by the bed ash amendment. © Williams & Wilkins 1998. All Rights Reserved.