Change Analysis of Cotton Soil Organic Carbon and Total Nitrogen and Carbon Storage in Manas River Valley
[Objective] The research aimed to study soil organic carbon and total nitrogen distribution in Oasis Cotton.[Method] Tianshan Mountains in Manas River Valley cotton fields as a research area,abandoned farmland as a control,with geographic methods,the distribution characteristics of cotton soil organic carbon and total nitrogen content in Manas River Valley cotton fields in last 23 years were investigated.[Result] Cotton soil organic carbon and total nitrogen content in Manas River Valley decreased with the increase of soil depth,and those in 0-30 cm soil layer were significantly higher than those in 30 cm below the soil.Organic carbon storage tended to increase.Soil organic carbon and total nitrogen in abandoned farmland in vertical distribution was also found,and with the increase of soil depth,decreased significantly,and soil organic carbon content in abandoned farmland showed a decrease trend month by month.However,cotton soil organic carbon storage firstly decreased and then increased in the case.Namely,in the early growth of cotton,0-30 cm and 30-100 cm soil organic carbon decreased to the lowest in the bloom stage.And with the reproductive growth of cotton into the later stages,organic carbon showed an increasing trend,abandoned farmland soil organic carbon storage showed a decreasing trend monthly because there was no input of plant litter.There were significant differences between two organic carbon contents.[Conclusion] Oasis cotton soil organic carbon content and total nitrogen content were significantly higher than those in abandoned farmland,soil organic carbon storage tended to increase,and occurred mainly in 0-30 cm.However,at 30-100 cm soil organic carbon,total nitrogen content change were insignificant.