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ARS Home » Midwest Area » St. Paul, Minnesota » Soil and Water Management Research » Research » Publications at this Location » Publication #116394
Title: CHARACTERIZATION OF HUMIC SUBSTANCES FROM AN AGRICULTURAL SOIL

Author
item Clapp, Charles
item BLOOM, B - UNIVERSITY OF MINNESOTA
item HAYES, MHB - UNIVERSITY OF LIMERICK
item BRUNETTI, G - UNIVERSITY OF BARI
item HAYES, T - UNIVERSITY OF LIMERICK
item HATCHER, P - OHIO STATE UNIVERSITY
item HORMANN, C - UNIVERSITY OF MINNESOTA
item Dowdy, Robert

Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/5/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Soil samples from a long-term experiment on tillage and nitrogen management under continuous corn (13 yr) and later cropped to soybean (6 yr) were extracted by a modified IHSS procedure to isolate the humic substances as related to the different management systems. Corresponding humic fractions were also isolated from an adjacent N-15-labeled long-term experiment. The ehumic acids (HAs) were purified by membrane-filtration, reprecipitated, dialyzed, and freeze-dried. Elemental analysis data showed minor differences between HAs, with residue-return samples having higher C and N values. Differences were also noted between residue removed- and residue- return treatments for carbohydrates, amino acids and acidity contents. FTIR, fluorescence, and CPMAS 13-C-NMR spectra provided valuable characterization and compositional information.