Effect of Phosphorous Fertilization on Zinc Sorption in Some Calcareous Soils From Iran

In this study phosphorous fertilization effect on Zn sorption was investigated. Ten composite samples (each from one soil series) located at Tehran province were collected and mixed with P-fertilizer (KH2PO4) and incubated for two weeks at 25 ºC ±. Added phosphorous levels were 0،00 and 000 mgPkg- and Zn levels ranged from to 60 mgZn L-. Phosphorous did not change the L –type zinc isotherm. Analysis of variance indicated that applying phosphorous to the soils at various levels showed no significant effect (p=0. 56) on zinc sorption. With increasing applied phosphorous، zinc sorption slightly reduced which was not significant. In most of the soil series، phosphorous reduced Freundlich isotherm constants. Phosphorous at low level، namely 00 mg P kg-، increased the two surface Langmuir sorption maxima b + b2. At 000 mg P kg- level، the afore-mentioned constants were reduced.