Ammonium Nitrogen Adsorption-Desorption Characteristics and Its Hysteresis of Typical Soils from Guanzhong Basin, China

The adsorption-desorption characteristics and desorption hysteresis of ammonium nitrogen were studied in typical soil collected from-the. Guanzhong Basin. The effects of soil texture, pH and-temperature on adsorption-desorption ammonium nitrogen were also discussed. The result showed that the Langmuir Model fitted the adsorption of Clay and fine sand and the Henry model fitted the adsorption of silty clay and silty sand, The Langmuir Ext1 model fitted desorption of clay and the Henry model fitted desorption of others three soils. The values of desorption rate for Clay, silty clay, silty sand and fine sand been 10, 28, 43 and 66 % in sequence. The content of Clay minerals Mid organics were positively correlated With the adsorption of ammonium nitrogen. The ammonium nitrogen adsorption by four Soils all increased as solution pH increased. The effect of temperature on the ammonium nitrogen adsorption was More significant than the capacity desorption.