Phosphorus Form Characteristics And Its Adsorption-Desorption Kinetics On Rhizosphere Soil In Tea Garden Of South China

Tea trees characterises acid and aluminum soil, the aluminum and phosphorus can both promote the growth of tea tree, improve the tea quality and enhance the production of tea.The phosphorus was prone to chemic reaction with aluminum and be fixed in acid soil which limited the crop growth.In order to explore the phosphorus’s morphological characteristics and adsorption-desorption processes and supplied mechanism of tea rhizosphere soil, the phosphorus form characteristics and adsorption-desorption processes and kinetics were studied in tea rhizosphere soil derived the different parent materials and cultivation years tea garden, using the Zhang Shoujing and Jackson method and adding phosphorus culture desorption experiments.Then, the least squares method was used to fitted the isotherms of phosphorus adsorption-desorption kinetics, the phosphorus morphological characteristics and adsorption-desorption characteristics of tea rhizosphere soil was discussed at last.The main outcome are outlined below:The all kind fractionations of inorganic phosphorus contents in rhizosphere soil were higher than non-rhizosphere soil. The inorganic phosphorus contents of tea rhizosphere soil that derived different fractionation was in order to Ca-P (Calcium phosphate (magnesium) compounds)>Fe-P(Iron phosphate compounds)>Al-P(Aluminum phosphate compounds)>O-P (the concentration of Occluded-P).The order of the inorganic phosphorus contents was the Slate> Granite> Quaternary red clay in tea rhizosphere soil which derived different parent material. The content of Fe-P was increased continued arid the contents of Ca-P, Al-P, O-P were increased at first and then decreased at last with the increase of the planting years, but different kind parent material soil had different characteristics.The results showed that the clear differences of phosphorus adsorption process and dynamics were observed between tea tree rhizosphere soil and non-rhizosphere soil and suggested that the phosphorus adsorption ability was lower and the phosphorus bioavailability is higher in tea rhizosphere soil than the non-rhizosphere soil. The order of the phosphorus adsorption ability was Quaternary red clay> Granite> the Slate in tea rhizosphere soil which derived different parent material. The DPS of rhizosphere soil was increased, but the MBC and Xm were decrease with the increase of the planting years.There were clear differences of phosphorus desorption process and kinetics were found between tea tree rhizosphere soil and non-rhizosphere soil and revealed the phosphorus desorption ability of tea rhizosphere soil was significantly higher than that of the non-rhizosphere soil. The phosphorus desorption ability of tea rhizosphere soil that derived different parent material was in order to Granite (the β was0.0048), Quaternary red clay (the β was0.0036), and the Slate(the β was0.0019). The Olsen-β and phosphorus desorption ability was increased with the increae of the cultivation years3kinds parent material rhizosphere soil.