caa a22 4500 477111130 CHVBK 20180405111609.0 cr unu---uuuuu 170330e19960201xx s 000 0 eng 10.1007/BF00011643 doi (NATIONALLICENCE)springer-10.1007/BF00011643 The effects of humic substances within the Ah horizon of a Calcic Luvisol on morphological changes related to invertase and peroxidase activities in wheat roots [Elektronische Daten] [G. Concheri, S. Nardi, F. Reniero, G. Dell' Agnola] The chemical and biological characteristics of humus within the Ah horizon (Calcic-Luvisol) have been studied. Attention was paid to variation in the NMR spectra of humic fractions and δ 13C values and to how these changes are related to different biological humic fraction activities. The chemical changes in particular involve the decrease of the aromatic component and the increase of the non-aromatic component within the horizon and the different δ 13C value not only within the horizon but also among the humic fractions distinctive of different molecular sizes. An attempt has been made to explain the vertical chemical changes in terms of processes affecting the biological characteristics of the high and low molecular size humic fractions. The main conclusions are that the low molecular size humic fractions, in the upper part of the horizon, are of greater importance with respect to the other humic fractions in influencing the enzyme activities linked to growth metabolism. The biological role of the high molecular size humic fractions characterised by a relevant content of peptidic- and carbohydratic-C is also presented. Kluwer Academic Publishers, 1996 δ 13C nationallicence humic fractions nationallicence invertase and peroxidase activities nationallicence NMR spectra nationallicence root hairs nationallicence scanning electron micrograph nationallicence wheat roots nationallicence Concheri G. Dipartimento di Biotecnologie Agrarie, Universitá di Padova, via Gradenigo 6, 35131, Padova, Italia aut Nardi S. Dipartimento di Biotecnologie Agrarie, Universitá di Padova, via Gradenigo 6, 35131, Padova, Italia aut Reniero F. Dipartimento Laboratorio di Analisi e Ricerche, Instituto Agrario, 38010, San Michele all'Adige (Trento), Italia aut Dell' Agnola G. Dipartimento territorio e sistemi agro-forestali, Universitá di Padova, via Gradenigo 6, 35131, Padova, Italia aut Plant and Soil Kluwer Academic Publishers; gopher://gopher.wkap.nl 179/1(1996-02-01), 65-72 0032-079X 179:1<65 1996 179 11104 https://doi.org/10.1007/BF00011643 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00011643 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Concheri G. Dipartimento di Biotecnologie Agrarie, Universitá di Padova, via Gradenigo 6, 35131, Padova, Italia aut NATIONALLICENCE 700 1- Nardi S. Dipartimento di Biotecnologie Agrarie, Universitá di Padova, via Gradenigo 6, 35131, Padova, Italia aut NATIONALLICENCE 700 1- Reniero F. Dipartimento Laboratorio di Analisi e Ricerche, Instituto Agrario, 38010, San Michele all'Adige (Trento), Italia aut NATIONALLICENCE 700 1- Dell' Agnola G. Dipartimento territorio e sistemi agro-forestali, Universitá di Padova, via Gradenigo 6, 35131, Padova, Italia aut NATIONALLICENCE 773 0- Plant and Soil Kluwer Academic Publishers; gopher://gopher.wkap.nl/ 179/1(1996-02-01), 65-72 0032-079X 179:1<65 1996 179 11104 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer