title: Dynamics of soil organic and inorganic carbon in the cropland of upper Yellow River Delta, China.
abstract: Soil inorganic carbon (SIC) and organic carbon (SOC) are important carbon reservoirs in terrestrial ecosystems. However, little attention was paid to SIC dynamics in cropland. We conducted a survey in the upper Yellow River Delta of North China Plain. We collected 155 soil samples from 31 profiles, and measured SOC, SIC and soluble Ca2+and Mg2+contents. Our results showed that mean SOC content decreased from 9.30 g kg-1near the surface to 2.36 g kg-1in 80-100 cm whereas mean SIC content increased from 10.48 to 12.72 g kg-1. On average, SOC and SIC stocks over 0-100 cm were 5.73 kg C m-2and 16.89 kg C m-2, respectively. There was a significantly positive correlation (r = 0.88, P < 0.001) between SOC and SIC in the cropland. We also found that SIC had a significantly positive correlation with both soluble Ca2+(r = 0.57, P < 0.01) and Mg2+(r = 0.43, P < 0.05). Our study suggested that increasing SOC might lead to an increase in SIC stocks in the cropland of North China Plain. This study highlights the importance of SIC in the carbon cycle of China's semi-arid region.
authors: College of Global Change and Earth System Science, Beijing Normal University, Beijing, 100875, China.
authors: Yang
authors: Y
authors: Guo
authors: College of Global Change and Earth System Science, Beijing Normal University, Beijing, 100875, China.
authors: Xiujun
authors: X
authors: Wang
authors: College of Global Change and Earth System Science, Beijing Normal University, Beijing, 100875, China.
authors: Xianglan
authors: X
authors: Li
authors: College of Agriculture, Shihezi University, Shihezi, 832000, China.
authors: Jiaping
authors: J
authors: Wang
authors: Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors: Minggang
authors: M
authors: Xu
authors: College of Global Change and Earth System Science, Beijing Normal University, Beijing, 100875, China.
authors: Dongwei
authors: D
authors: Li