Humus status of postlithogenic arable mineral soils
Department of Soil Science and Agrochemistry, Estonian Agricultural University, Kreutzwaldi 64, 51014 Tartu, Estonia; e-mail: raimo@eau.ee
Abstract:
In the work soil organic carbon (SOC) and soil organic matter (SOM) contents of Estonian postlithogenic mineral arable soils are analysed by 13 soil groups, whereas the data are taken from the database PEDON. The SOC and SOM concentrations (g kg-1) and pools
(Mg ha-1) for Leptosols, Cambisols (3 groups), Luvisols (2 groups), Albeluvisols (3 groups) and Gleysols (4 groups) are presented separately for humus cover (HC) and soil cover (SC). On the basis of different soil type characteristics and their distribution, superficies the SOC and SOM pools for the whole Estonian arable land were calculated. It was revealed that in the studied part of Estonian arable soils or in arable SC (forming 85.8% of total arable land) 86.4 +/-13.1 Tg of organic carbon is sequestrated, from which 77.3% is situated in HC and 22.7% in subsoil. This quantity of SOC is sequestrated into 149 +/- 25 Tg SOM. The generalisation of the data received by different soil types, as well as elucidation of pedoecological regularities is performed on the background of Estonian postlithogenic soil matrix. The characterisation of HC quality is done on the basis of arable soils HC classification.
Key words:
arable soils, carbon sequestration, humus cover type, matrix of postlithogenic soils, SOC and SOC concentration and pools, soil humus status