Inorganic Nitrogen Determined by Laboratory and Field Extractions of Two Forest Soils
Van Miegroet H. 1994. Inorganic Nitrogen Determined by Laboratory and Field Extractions of Two Forest Soils. Soil Science Society of America Journal. 59(2):549-553
ABSTRACT: To assess the effect of a delay in soil processing on inorganic N levels in N-rich soils, field and laboratory extractions were compared at two forested sites with high N mineralization and nitrification potential. At eight sampling dates in 1989 and 1990, five mineral soil cores per site were taken between 0- and 10-cm depth and transported on ice to the laboratory for KCl extraction and NH4-N and NO3-N analysis. At three sampling dates in 1990, soil extractions were performed in the field immediately following sampling, and inorganic N concentrations were compared between extractions. Nitrate-N increased four- to sevenfold (net release of 2–7 mg NO3-N/kg dry soil) due to the transport and relatively short delay (<24 h) in the processing of the soil samples, either coinciding with increased net N mineralization or due to transformation of NH4-N into NO3-N. This study indicates that if possible, soil samples should be extracted in the field, especially at N-rich sites. The concerns raised by this study may not necessarily apply to N-poor soils characterized by slow N transformation rates.
- Type
- Journal Article
- Authors
- Van Miegroet, Helga
- Units
- GRSM
- Keywords
- APHN, Appalachian Highlands Network, Clingmans Dome, Great Smoky Mountains National Park, GRSM, GRSM-00762, nitrogen, SER, soils, Southeast Region