| More than twice as much carbon is held in soils as in vegetation or the atmosphere, and the changes in soil carbon content can have a large effect on the global carbon budget. Soil organic carbon (SOC) storage in terrestrial and agricultural soils of China plays an important role in the global carbon cycle. Moreover, agricultural soil is the most active part. Management practices of tillage, fertilization and irrigation can influence the level and quality of SOC of China, having effects on soils fertility and crop yield, as well as on global environment.Based on the first and the second national soil inventory database, obtained from direct field measurements and some references, the SOC database was been developed to estimate SOC storage and its spatiotemporal distributions in China in 1960s and afterwards. Furthermore, the methods has been proposed to calculate the SOC storage in China.The results showed that SOC storage in China increased 1 Pg from 1960s to 1980s, but the status of carbon sink/source was not significant. The SOC content of agriculture in China decreased from 23.0 g.kg-1 in 1960s to 15.0 g.kg-1 in 1980s, and increased to 21.2 g.kg-1 in 2000s on average, mainly due to the changes in land use, population growth, and economic policy changes. The estimated carbon sequestration potential in cropland soil of China was about 0.7 PgC during 1980s to 2000s, mean that cropland soil of China were turned into carbon sink during the period.This paper based on background information of the 1960s' national soil inventory database discusses: 1) the spatiotemporal distributions, 2) the changes of SOC in Chinese terrestrial and agricultural soils in 1960s and afterwards, and 3) their impacts on global carbon budget. The study provides the methods and information for better understanding of the processes of soil organic carbon changes and the potentials of carbon sinks/sources in agricultural soils in China during the last 40 years. These can help develop suitable agricultural management practices and effective policy strategies to facilitate soil carbon sequestration and emissions mitigation for sustainable agriculture in China. |
