Soil organic carbon distribution and storage along reclamation chronosequences in a typical coastal farming area, Eastern China

Soil organic carbon (SOC) is an important indicator for soil quality evaluation. It is closely associated with soil fertility, and also has a great impact on the terrestrial carbon cycle. In this study, the distribution and storage of SOC were evaluated at the different reclamation chronosequences [(a) 2004–2007, (b) 1995–2004, (c) 1955–1995, (d) 1024–1955, and (e) < 1024)] in Dongtai City of Jiangsu Province, Eastern China. The results showed that the average SOC content ranged between 3.98 and 8.49 g/kg, which declined with the increase of soil depth. The soil bulk density exhibited the opposite trend, and had only a slight change throughout the entire study area. Both the SOC content and soil density decreased as the reclamation age increased. The SOC content were significantly higher under the 1024–1955 and < 1024 reclamation stages than the other reclamation stages. The storage of SOC in the study area was 8.03 × 105 kg at the 0–40 cm soil depth, with a SOCD of 3.07 kg/m2, which was markedly lower than the mean value in Jiangsu Province. It was concluded that the SOC storage increased proportionally to the reclamation age, and notable potential for carbon sequestration was expectable in the coastal farming area, Eastern China.