Estimates Of Soil Carbon In Cultivated Land Of Sangzhi County

Soil organic carbon is important part of the terrestrial carbon cycle. The arable land is affected obviously not only by human activities, but also its carbon storage plays an important role in terrestrial organic carbon, So the study of soil carbon storage is of great significance. The soil organic carbon content of plowed layer and its reserves was studied, based on the method of GIS technology and models in cultivated soil Sangzhi County, Hunan Province, the research results are as follows:1. The average of soil organic carbon was15.50g/kg in plowed layer soil,17.26g/kg in the paddy field and13.28g/kg in dry land in Sangzhi County. The area that the content of soil organic matter ranged from11.6to17.4g/kg accounted for55.76%of the arable land. The largest area that soil organic carbon content was greater than18.5g/kg was Yellow limestone soil.2. The obvious spatial characteristics of the organic carbon content were observed in Sangzhi County. The township whose carbon content area was higher than18.5g/kg has the biggest area was Sha Ta Ping Township.followed by He Kou Township, Shang He Xi Township and Jian Jia Po Township; The elevation, terrain parts, soil parent material and texture were play important role to affected soil organic carbon content. Organic carbon content becomes bigger with the increase of the elevation and slope, the sun organic carbon content was significantly higher than the Yin slope, Low GangDe and closed the depressions organic carbon content were higher.3. SangZhi arable land top layer soil organic carbon reserves total of718.848×103t, the average of organic carbon density was31.67t/hm2, the highest organic carbon density of the white magnetic sand and mud, reaching46.49t/hm2. White Soil and between sandpurple tidal soil organic carbon density, were respectived reached45.69t/hm2and45.56t/hm2, Yellowstone lime soil organic carbon reserves reached104.169×103t followed by acid purple clay soil and gray Wong Nai reserves were42.223×103t and38.152×103t.4. The obvious spatial characteristics of the organic carbon density were observed in Sangzhi County, organic carbon density of the Ba Da Gong Shan Township reached43.07t/hm" and followed by Jian Jia po Township and Ba Mao Township, which were respectively reached40.40t/hm2and39.66t/hm2and; Organic carbon storage was Sha Ta Ping Township which reached40.5×103t, followed by Li Yuan Township and Chen Jia He Township, were respectively reached32.98×103t and32.81×103t.