[Research on vertical distribution pattern and reserve of organic carbon in paddy field soil of Qianguo, Jilin].

Taking Qianguo paddy field of Jilin Province as investigation object, based on the soil test data of 7 different periods developed for 4 to 55 years, the vertical distribution of SOC content in the 1 m paddy field section was studied adopting the space scale method instead of time scale. The paddy soil carbon sink in last 20 years was discussed and the organic carbon storage of Qianguo paddy field soil was estimated. According to the second soil census data, the characteristics of soil SOC used in fields of different type were comparatively analyzed. The results showed that the paddy field SOC decreased from top to bottom by layer, which showed an increasing trend with the increase of development age; the organic carbon content in the surface soil layer (0-30 cm) (1 820.79 t) was 46.87% of the total organic carbon storage in deep soil (3 885.05 t), and the soil SOCD content was highly different depending on the type of field, ranked in descending order as paddy field, dry land, and saline field. The development of paddy field is a SOC accumulating carbon sink process, which is conducive to the transfer of organic carbon from the surface soil layer to the bottom soil layer.