Organic matter of Estonian grassland soils

R. Kõlli, T. Köster and K. Kauer

Department of Soil Science and Agrochemistry, Estonian University of Life Sciences,Kreutzwaldi 1, 51014, Tartu, Estonia; e-mail: raimo.kolli@emu.ee

Abstract:

Soil organic carbon (SOC) and soil organic matter (SOM) contents of Estonian grassland soils are analysed in 20 soil groups using data from the database PEDON and CATENA. The SOC and SOM concentrations (g kg-1) and pools (Mg ha-1) for upland mineral soils (Leptosols, Cambisols, Luvisols, Albeluvisols, Regosols; total 9 groups), lowland mineral soils (Gleysols, Fluvisols; 9 groups) and wetland organic soils (Histosols; 2 groups) are given separately for humus cover (HC) and soil cover (SC). The SOC and SOM pools for the entire Estonian grasslands were calculated on the basis of different soil types, morphological characteristics and distribution superficies. It was concluded that in Estonian grasslands SC 39.9±8.0 Tg of organic carbon is sequestered, 76.2% of which is found in HC and 23.8% in subsoils. Grassland SOC is sequestered in 69.1±12.6 Tg of SOM. A quality analysis of humus covers of grassland soils (evaluated from the pedo-ecological perspective) distinguished 5 quality groups and 15 subdivisions.

Key words:

Humus status of postlithogenic arable mineral soils

R. Kõlli and O. Ellermäe

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