caa a22 4500 477109438 CHVBK 20180405111604.0 cr unu---uuuuu 170330e19960601xx s 000 0 eng 10.1007/BF00010450 doi (NATIONALLICENCE)springer-10.1007/BF00010450 Cultivation effects on the nature of organic matter in soils and water extracts using CP/MAS 13C NMR spectroscopy [Elektronische Daten] [Armando Lessa, Darwin Anderson, Brock Chatson] The objective of this study was to examine the chemical structure of the organic matter (SOM) of Oxisols soils in slash and burn agriculture, in relation to its biological properties and soil fertility. The CP/MAS 13C technique was used to identify the main structural groups in litter and fine roots as SOM precursors; to identify the changes on the nature of the SOM upon cultivation and the proportion of labile and stable components; and to identify the nature of the organics present in water extracts (DOC). Carbohydrates were the main structural components in litter whereas components such as carbonyl C, carboxyl C,O-alkyl C and alkyl C were more common in SOM. Phenolic C and the degree of aromaticity were similar in litter and SOM. Cultivation resulted in a small decrease in the relative proportion of carbohydrates in SOM, little change in the levels of O-alkyl C and carbonyl C, but an increase in carboxyl C, phenolic C and aromaticity of the SOM. The level of alkyl C in soil was higher than the level of O-alkyl C, indicating the importance of long-chain aliphatics along with lignins in the stabilization of the SOM in Oxisols. The SOM of Mollisols from the Canadian Prairies differed from the Oxisol, with a generally stronger expression of aromatic structures, particularly in a cultivated soil in relation to a native equivalent. Carbohydrate components were the predominant structures in the DOC, indicating their importance in nutrient cycling and vertical translocations in the Oxisol. Kluwer Academic Publishers, 1996 CP/MAS 13C nationallicence root/litter nationallicence soil organic matter nationallicence water dissolved organic carbon nationallicence Lessa Armando Soil Science Department, University of Saskatchewan, S7N OWO, Saskatoon, SK, Canada aut Anderson Darwin Soil Science Department, University of Saskatchewan, S7N OWO, Saskatoon, SK, Canada aut Chatson Brock Plant Biotechnology Institute, National Research Council, 110 Gymnasium Place, S7N OWO, Saskatoon, SK, Canada aut Plant and Soil Kluwer Academic Publishers; gopher://gopher:wkap.nl 184/2(1996-06-01), 207-217 0032-079X 184:2<207 1996 184 11104 https://doi.org/10.1007/BF00010450 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00010450 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Lessa Armando Soil Science Department, University of Saskatchewan, S7N OWO, Saskatoon, SK, Canada aut NATIONALLICENCE 700 1- Anderson Darwin Soil Science Department, University of Saskatchewan, S7N OWO, Saskatoon, SK, Canada aut NATIONALLICENCE 700 1- Chatson Brock Plant Biotechnology Institute, National Research Council, 110 Gymnasium Place, S7N OWO, Saskatoon, SK, Canada aut NATIONALLICENCE 773 0- Plant and Soil Kluwer Academic Publishers; gopher://gopher:wkap.nl/ 184/2(1996-06-01), 207-217 0032-079X 184:2<207 1996 184 11104 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer