Soil management effects on organic carbon in isolated fractions of a Gray Luvisol


Autoria(s): Plante, Alain F.; Stewart, Catherine E.; Conant, Richard T.; Paustian, Keith; Six, Johan
Data(s)

2006

Resumo

Agricultural management affects soil organic matter, which is important for sustainable crop production and as a greenhouse gas sink. Our objective was to determine how tillage, residue management and N fertilization affect organic C in unprotected, and physically, chemically and biochemically protected soil C pools. Samples from Breton, Alberta were fractionated and analysed for organic C content. As in previous report, N fertilization had a positive effect, tillage had a minimal effect, and straw management had no effect on whole-soil organic C. Tillage and straw management did not alter organic C concentrations in the isolated C pools, while N fertilization increased C concentrations in all pools. Compared with a woodlot soil, the cultivated plots had lower total organic C, and the C was redistributed among isolated pools. The free light fraction and coarse particulate organic matter responded positively to C inputs, suggesting that much of the accumulated organic C occurred in an unprotected pool. The easily dispersed silt-sized fraction was the mineral-associated pool most responsive to changes in C inputs, whereas the microaggregate-derived silt-sized fraction best preserved C upon cultivation. These findings suggest that the silt-sized fraction is important for the long-term stabilization of organic matter through both physical occlusion in microaggregates and chemical protection by mineral association.

Formato

application/pdf

Identificador

http://eprints.qut.edu.au/37770/

Publicador

Agricultural Institute of Canada

Relação

http://eprints.qut.edu.au/37770/1/c37770.pdf

DOI:10.4141/S05-037

Plante, Alain F., Stewart, Catherine E., Conant, Richard T., Paustian, Keith, & Six, Johan (2006) Soil management effects on organic carbon in isolated fractions of a Gray Luvisol. Canadian Journal of Soil Science, 86(1), pp. 141-151.

Direitos

Copyright 2006 Agricultural Institute of Canada

Fonte

Institute for Sustainable Resources

Palavras-Chave #050100 ECOLOGICAL APPLICATIONS #050300 SOIL SCIENCES #Soil organic C, tillage, residue management, N fertilization, silt, clay
Tipo

Journal Article