Abstract: The complexes with differently combined humic substance and organo-mineral complexes were investigated using two ways of analysis,which was general analysis on common chemical properties and thermo analysis on thermodynamic properties.The results showed that using organic matter in a long-term obviously raised the contents of organic carbon,with the amount of water-scattered complex ( G0 fraction) descended,while water-stable complex (Gl,G2 fraction) raised.With the application of organic manure,the content of organic carbon in three kinds of colloid-combined complexes and loose-combined carbon in its heavy fraction were increased.The organic manure could not only improve the total energy level (higher level of enthalpy) of soil organo-mineral complexes,but also improve the energy level of loose,stable and tightly-combined humic.Organic manure also had influence on common soil fertility parameters,i.e.the contents of total nitrogen,total phosphorus,content of exchangeable cation(CEC) and C/N specific ratio were all improved.

Key words: Farmland ecosystem, CO₂ flux, Transitional cal culation