The long-term use of cropland and cropland reclamation caused a decreasing trend in soil organic carbon (SOC) stock. However, studies on the effects of plant recovery on SOC changes are rare.
A research team led by Prof. Song Kaishan from the Northeast Institute of Geography and Agroecology (IGA) of the Chinese Academy of Sciences completed SOC mapping in Northeast China from 1985 to 2020 and took different reclamation periods based on Landsat images and land cover data. The study was published in Biology of Climate Change on June 25.
The researchers found that high SOC is mainly distributed in black soils and eastern Heilongjiang Province, and low SOC is mainly distributed in mountainous areas. The maximum SOC content is more than 40 g kg-1and the lowest SOC content is less than 5 g kg-1 in Northeast China. Nearly 64% of the cropland has a decreasing trend for SOC content, and the largest SOC loss is more than 15g kg-1 in some regions.
Environmental factors (precipitation and temperature) mainly affect the spatial changes in SOC, and have little effect on temporal changes. In contrast, social factors (irrigation area, agricultural machinery, fertilizer consumption and rural people) dominate the temporal variation of SOC.
Vegetation reclamation had the greatest effect on wetlands, and the recovery period of years 31-35 from wetlands led to 16.05 Mg C ha-1 Loss of SOC density.
The study provides a reference for SOC change in the black soil region of Northeast China and will attract more attention to the area of protection of “black soils” and natural ecosystems.
Xiang Wang et al, Effects of cropland reclamation on soil organic carbon in the black soil region of China over the past 35 years, Biology of Climate Change (2023). DOI: 10.1111/gcb.16833
Awarded by the Chinese Academy of Sciences
Citation: Study reveals effects of cropland reclamation on soil organic carbon in black soil region of China (2023, July 18) retrieved 19 July 2023 from https://phys.org/news/2023-07- reveals-effects-cropland-reclamation-soil .html
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