Abstract: By using the balance method, we investigated the effects on the adsorption\|desorption characteristics of phosphorus in black soil with the biochars from different addition mass fraction  and different sources (corn stalk, husk, pine). The results show that with the increase of the addition mass fraction of biochars, the amount of phosphorus adsorption in the black soil increase first and then decrease. When the mass fraction of 1.2% is added, the phosphorus adsorption capacity of black soil is maximum. The  adsorption capacity of different biochars on phosphorus in black soil is as follows: pine>corn stalk>husk. The black soil mixed with pine biochar on phosphorus adsorption capacity is the largest, which value is 0.697 mg/g. Phosphorus adsorption and desorption capacity is increased with mass concentration of phosphorus solution increased, but the rate of increase is gradually smaller. The isothermal adsorption curve of phosphorus in block soil conforms to the Langmuir adsorption equation.

Key words: phosphorus, black soil, adsorption-desorption, biochar