Plant Soil Environ., 2011, 57(5):193-200 | DOI: 10.17221/453/2010-PSE

Relationships between quality and quantity of soil labile fraction of the soil carbon in Cambisols after liming during a 5-year period

L. Kolář¹, V. Vaněk², S. Kužel¹, J. Peterka¹, J. Borová-Batt¹, J. Pezlarová¹

¹ Department of Applied Plant Biotechnologies, Agricultural Faculty, University of South Bohemia in České Budějovice, České Budějovice, Czech Republic

² Department of Agroenvironmental Chemistry, and Plant Nutrition, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Prague, Czech Republic

The labile fraction of soil organic carbon (SOC) in terms of its quantity is a sensitive but dynamic indicator of the reactive agent in soils. If it is to be considered as a feature of soil quality, the value of its quantity should be completed by data on its quality. It can be expressed by the value of the rate constant of microbial oxidation k_bio of this fraction or by data on chemical stability during hydrolysis or oxidation. If the quality of SOC labile fraction is not determined, at least the ratio of C_MIC: C_org should be given. The adjustment of soil acidity increases the microbial activity of soils, therefore the quantity of SOC labile fraction decreases and at the same time kbio decreases proportionately to the increasing stability of soil organic matters. During a 5-year period after the liming the soils acidify again and this process passes the faster the lesser their ion exchange capacity and buffering are. The quantity of the labile fraction of SOC raises again, its stability decreases and k_bio raises again. The conversion pH value has secondary relevance.

Keywords: soil organic carbon (SOC); labile fraction SOC; quality and quantity; effect of soil reaction adjustment; time changes

Published: May 31, 2011  Show citation