KBS021: Soil Inorganic N
In use from sometime
Abstract
Sampling Frequency: Monthly (1989 to 1995); bimonthly 1996 to present
Triplicate subsamples (10 g fresh weight) from the composite soil sample of each plot are extracted with 100 mL of 1 M KCl . Soil extracts are shaken for 1 minute and allowed to sit overnight and re shaken before filtering . Soil extracts are filtered with a syringe filter using a Type A/E, 1um pore size, glass fiber filter . Filtrates are stored in 7 mL scintillation vials and refrigerated until analysis for NH 4 + and NO 3 - are completed . Both analyses are performed on a Flow Injector Analyzer (NH 4 + via diffusion colorimetry technique and NO 3 - via cadmium reduction and colorimetry) .
Protocol
Author: Tim Bergsma
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