Relationships between quality and quantity of soil labile fraction of the soil carbon in Cambisols after liming during a 5-year period
L. Kolář, V. Vaněk, S. Kužel, J. Peterka, J. Borová-Batt, J. Pezlarováhttps://doi.org/10.17221/453/2010-PSECitation:Kolář L., Vaněk V., Kužel S., Peterka J., Borová-Batt J., Pezlarová J. (2011): Relationships between quality and quantity of soil labile fraction of the soil carbon in Cambisols after liming during a 5-year period. Plant Soil Environ., 57: 193-200.
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 kbio 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 CMIC: Corg 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 kbio 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