Abstract: The characterization of adsorption and desorption of soil phosphorus is investigated in the 26th year of long-term fertilization south yellow soil. The result indicated that there is good fitness between the adsorbed curves of the Langmuir equation phosphorus and the Langmuir equation(P0.01). Compared with single fertilization, long-term applying of both fertilizer and dairy manure or straw can decrease K、MBC and crease DPS. However, there is a crosscurrent between Xm. P which will be desorbed more easily under the combined application of fertilizer and dairy manure when its concentration is low, and that will be opposite as the concentration ascends. Under the combined application of organic fertilizer and chemical fertilizer, P acts as a headstream with a low concentration while it acts as a sea with a high concentration.