СЭЛЭНГЭ АЙМГИЙН АЛТАНБУЛАГ СУМЫН ТАРИАЛАНГИЙН ХӨРСНИЙ ОРГАНИК НҮҮРСТӨРӨГЧИЙН НӨӨЦ, ӨӨРЧЛӨЛТ

This study aimed to identify soil organic carbon stocks in croplands and pasture area of Altanbulag soum of Selenge province in the northern part of Mongolia. Based on historical soil data, which was collected in 1977. In order to reveal soil organic carbon changes between 1977 and 2019, we chose 10 sampling locations from these soil data and collected 32 soil samples from the 0-20 cm, and 20-40 cm depth of soil layers in 2019. Results showed that the organic carbon content of 0-20 cm depth of cropland soil layer decreased by 15.4 % in 2019 (21.85 t ha-1) compared to 1977 (25.8 t ha-1). Besides, soil organic carbon content for 0-20 cm depth of cropland soil layer was reduced by 51.8 %, which was reduced by 0.8 % for 20-40 cm depth of cropland soil layer compared to those results of soils of pasture land.