Abstract:

To explore the variation characteristics of organic carbon of arable black soil in Suihua City of Heilongjiang Province, the content of soil organic carbon in 2002 and 2019 were compared to clarify the temporal and spatial variation characteristics of organic carbon. The results showed that the average organic carbon content of arable black soil in Suihua City in 2002 was 22.02 g/kg, and the coefficient of variation was 22.57%. The average organic carbon content in 2019 was 21.67 g/kg, and the coefficient of variation was 22.47%. The organic carbon content in 2002 and 2019 belonged to medium variation. The average organic carbon content only increased in Wangkui County and Beilin District, by 2.96 g/kg and 0.13g/kg, respectively. The average organic carbon content in Lanxi County, Suiling County, Qing’an County, Qinggang County, Hailun City and Mingshui County decreased by 1.91, 1.72, 1.45, 0.46, 0.44 and 0.32 g/kg, respectively. According to the nutrient classification standard, the organic carbon content in Suihua was at the third and fourth level in 2002 and 2019. In view of the spatial variation, the organic carbon first decreased then increased from both sides to the middle and increased gradually from south to north. From 2002 to 2019, the organic carbon content of arable black soil in Suihua showed a downward trend, the nutrient classification of organic carbon did not change in the 17 years and the spatial distribution trend of organic carbon did not change significantly.

Key words: Suihua City, arable black soil, organic carbon, distribution characteristics, spatial heterogeneity