Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Sizes and shapes of humic substances
Autore:
Clapp, CE; Hayes, MHB;
Indirizzi:
Univ Minnesota, USDA ARS, St Paul, MN 55108 USA Univ Minnesota St Paul MNUSA 55108 sota, USDA ARS, St Paul, MN 55108 USA Univ Minnesota, Dept Soil Water & Climate, St Paul, MN 55108 USA Univ Minnesota St Paul MN USA 55108 ater & Climate, St Paul, MN 55108 USA
Titolo Testata:
SOIL SCIENCE
fascicolo: 11, volume: 164, anno: 1999,
pagine: 777 - 789
SICI:
0038-075X(199911)164:11<777:SASOHS>2.0.ZU;2-1
Fonte:
ISI
Lingua:
ENG
Soggetto:
ORGANIC-MATTER; ACIDS; SOIL; LIGNIN;
Keywords:
humic substances; macromolecules; soil organic matter; degradation; abiotic condensation; micelle; random coil;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
50
Recensione:
Indirizzi per estratti:
Indirizzo: Clapp, CE Univ Minnesota, USDA ARS, 1991 Upper Buford Circle, St Paul, MN 55108 USA Univ Minnesota 1991 Upper Buford Circle St Paul MN USA 55108 USA
Citazione:
C.E. Clapp e M.H.B. Hayes, "Sizes and shapes of humic substances", SOIL SCI, 164(11), 1999, pp. 777-789

Abstract

This series of papers focuses on considerations of the sizes and shapes ofhumic macromolecules. The initiative arose because of the divergent views held by participants at a symposium/workshop held under the auspices of theSoil Science Society of America and the International Humic Substances Society in Anaheim, CA in October 1997, Three different viewpoints were expressed, and each satisfied its proponent. One suggested that humic substances (HS) are macromolecular and assume random coil conformations in solution; asecond proposed that HS are molecular associations of relatively small molecules held together by weak interaction forces; a third considered that HSare in solution as micelle or "pseudomicellar" structures. Viewpoints two and three could be broadly considered to be under the same umbrella. We have considered the experimental procedures that led the proponents to their points of view, and we do not consider it to be our brief to side with one or another of the concepts. Much work remains to be done before a definitiveanswer is found. We understand that the various concepts arose from studies of different soils using different experimental techniques, and we share the view that the matter/controversy can best be resolved when data are available from applications of the same advanced techniques and procedures to a variety of HS from different sources. We are convinced that awareness of the sizes and shapes of humic molecules is of fundamental importance for anunderstanding of the many basic reactions and interactions that take placein the soil environment and that have considerable environmental significance. It is our hope that this series of papers will stimulate researchers to pool their views, skills, and instrumentation and set about finding a solution to this fundamental aspect of humic structures.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/12/20 alle ore 03:44:10