The Agricultural Upland Soil Carbon Cycle Research Of Longquan

The farmland ecosystem as an important part of the terrestrial ecosystem,isan important part of the terrestrial ecosystem carbon cycle research. Chengdu has636.1million mu of arable land, accounting for34.2%of the total area, is the mainsource of the Chengdu carbon output.This paper describes the progress of the study of the carbon cycle at home andabroad, and research purposes and research significance; The application mesh bagmethod Longquanyi District crops leaf litter decomposition in a six-month study,including the quality of the residual rate and weight loss rate determination litterdecomposition, litter decomposition rate model, the experimental soil properties, litterchemicalcomposition, biomass experimentally, experimental soil pH, soil moisture.Ultimately concluded that three crops: grapes, pumpkin, eggplant, leaf litter weightloss rate of two stages, the first stage （0-90days） for rapid weight loss stage, thesecond stage （after90days） for slow weight lossstage. Sampling in90days, threelitter residues are grapes85.35%> Eggplant85.15> Pumpkin79.95%; sampling of180days, all the litter residues are grapes grapes79.95%>74.8%eggplant, pumpkin73.85%. Average annual three litter decomposition rate were the pumpkin0.938>Eggplant0.893> grape0.811; the three litter half-life, turnover respectively grapet_0.5=1.17a,t9.5=2.62a, pumpkin t_0.5=0.86a,t9.5=1.84a, eggplant t_0.5=0.98a,t9.5=2.01a.Grape leaf litter N%content of0.5%, C/N100.8; the pumpkin leaf litter N%contentof0.61%, the C/N76.6; the eggplant leaf litter N%content of0.53%, the C/N91.7.This result with the past scholars litter initial higher the nitrogen content, C/N is lower,then the litter decomposition rate was faster results.