Study On Carbon Storage Of Cultivated Land Topsoil In Hunan Province

The cultivated land topsoil organic carbon storage is important part of terrestrial carbon cycle,it’s deeply influenced not only by human land use patterns but also its play an significant role in terrestrial ecosystem carbon storage,so the study of cultivated land topsoil organic carbon storage to grasp soil fertility and soil ecoregions is vital of significance.The article based on the method of GIS technology and models to estimates of cultivated soil layer organic carbon density and its reserves in Hunan province, the research results are as follows:1.The average of soil organic matter was 33.44g/kg in plowed layer soil, 35.1g/kg in the paddy field and 25.6g/kg in dry land in Hunan province. The highest soil local type that content of soil organic matter was black flat sand,its conent up to 55.65g/kg,followed by significant coal slime,reaching 51.95g/kg.The lowest cotent of soil organic matter was sand between purple alluvial soil only 12.50g/kg.2. The obvious spatial characteristics of the organic matter content were observed in Hunan province.The city whose organic matter content area was higher than 30g/kg has the biggerst numbers of sample was Chenzhou City,about 7.6% of all.followed by Shaoyang city and Yongzhou City were 7.1% and 6.9% respectively;The content of soil organic matter were obvious differences among region and soil species.3. The total organic carbon storage of arable land topsoil in Hunan 186.667* 106t, the average of organic carbon density was 45.27 t/hm2,the highest organic carbon density is red soil,reaching to 49.68t/hm,followed by yellow-brown soil and yellow soil organic carbon density were respectived reached 46.11 t/hm2 and 45.39 t/hm2;Paddy soil has the biggest organic carbon reserves reaching to 173.32x106t,followed by fluvo-aquic soil and red soil reserves were 2.22×106t and 5.59×106t.4. The obvious spatial characteristics of the organic carbon density were observed in Hunan province, organic carbon density of the Loudi City reached 49.34t/hm2and followed by Chenzhou City and Xiangtan City,which were respectively reached 48.54 t/hm2 and 47.56 t/hm2. Organic carbon storage was Shaoyang City which reached 21.80x106t,followed by Changde City and Yongzhou City,were respectively reached 19.32x106tand 18.10x10~6t.