The Difference of the Storage and Oxidation Stability of Soil Organic Carbon in the Soil Between Farmland and Orchards

The amount and properties of organic carbon under different land use types are popular concerned.With the different landuses of the farmland and orchards in southern region of loess plateau,the total soil organic carbon,readily oxidized and difficultly oxidized organic carbon were studied,and the oxidation stability and storage of soil organic carbon were calculated and compared.The results showed that although the content of total organic carbon in all orchards soil including new,fully bearing and old orchards was almost in the same level with that of the farmland soil,total organic carbon and easily oxidized organic carbon decreased with the aging of orchards.In the soil profile,total organic carbon,easily oxidized and difficultly oxidized organic carbon decreased with soil depth and orchards age,but the changes of Kos value were on the contrary.The order of soil organic carbon storage from 0 to 200 cm is farmland new orchard(less than 5 years) Full bearing period orchard(10-15 years) old orchard(above 15 years).Compared to the farmland,the storages of soil organic carbon in different soil profiles from 0 to 200cm were decreased by 6.1,9.3 and 22.4% in new orchards,fully bearing orchards and old orchards,respectively.This indicated that the storage of soil organic carbon reduced with the orchard age increase.