GYÖRGY FÜLEKY und LÁSZLÓ TOLNER

Gemeinsames Modell der P-Adsorption und P-Desorption im Boden

Composite model of P adsorption and desorption in the soil

The balance equation for the soil-soil solution system and the FREUNDLICH isotherm (for calculation of desorption) were used to calculate the portion of P supplied to the soil, which contributes to balancing the soil liquid und solid phases und which gets desorbed by multiple water extraction. Proceeding from this maximally desorbable P amount (= Q) it is possible to characterize adsorption and desorption processes with the help of one and the same curve, i. e. no hysteresis occurs. It is suggested that the maximally desorbable P amount may serve as an index of the plant-available soil P content.