100(3)_str29

ISSN 1392-3196 / e-ISSN 2335-8947
Zemdirbyste-Agriculture, vol. 100, No. 3 (2013), p. 227–234
DOI  10.13080/z-a.2013.100.029

Stability of soil organic carbon in agro and forest ecosystems on Arenosol

Kęstutis ARMOLAITIS, Jūratė ALEINIKOVIENĖ, Jadvyga LUBYTĖ, Vilma ŽĖKAITĖ, Paulius GARBARAVIČIUS

Abstract

The aim of the study was to assess the stability of soil organic carbon (SOC) in Arenosol (AR) under three different land uses: 1) continuous arable land, 2) abandoned for the last 15 years arable land, and 3) 50 years ago afforested with Scots pine (Pinus sylvestris L.) or silver birch (Betula pendula Roth) arable land. In the 0–10, 10–20 and 20–40 cm mineral soil layers the following was determined: 1) total SOC and humus fractional composition in bulk soil, 2) unprotected SOC (water extractable SOC and soil microbial biomass carbon (C_bio)), and 3) in physical fractions unprotected and protected from microbial decomposition SOC. Mean C_bio was the lowest in pine plantations, the highest in birch plantations and intermediate in arable or abandoned arable land. The highest concentrations of fulvic and humic acids and unprotected water extractable SOC were found in forest plantations. However, mineral topsoil after the afforestation, especially with birch, contained the highest concentrations of total SOC and the concentrations of SOC protected in soil organic matter (SOM) of silt + clay sized (<53 µm) fraction.

Our results confirmed the Kyoto Protocol’s provision that the afforestation of nutrient-poor sandy arable soils with birch could be relevant for soil carbon sequestration.

Key words: abandoned land, afforested land, arable land, unprotected and protected SOC.

Full text: 100_3_str29.pdf