The kinetics of soil available Phosphorus changes in presence of municipal solid waste compost in some calcareous soil of Iran

This study was done with the aim of investigating the kinetics of available phosphorus changes in treated soils with municipal solid waste compost، fertilizer and the mixture of these in two levels of first and second percent in eight calcareous soil samples and in a period of zero to 3600 hours in incubation conditions (FC moisture and 250c). The results showed that with time increasing، extractable phosphorus amount by Olsen decreased and increased in fertilizer and municipal solid waste compost treatment respectively in both level of one and two percent. Six mathematical equations (simplified Elovich، power function، parabolic diffusion، zero-order، first-order and second-order) were used to describe kinetics of conversion of available to unavailable phosphorus. The comparison of models showed that with the respect of coefficient of determination and standard error of the estimate، second order equation is the best equation to describe kinetics of extractable phosphorus changes in the all treatments. Also results showed that with increasing calcium carbonate equivalent، the conversion speed of available to unavailable phosphorus in fertilizer treatment and unavailable to available phosphorus in municipal solid waste compost treatment was increased significantly