Determination of soil standard phosphorus requirement with application of freundlich adsorption isotherm (case study of moghan plain)

The current research was conducted to analyze phosphor adsorption in soils of Moghan region. For this purpose, phosphor adsorption tests were carried out on four soil samples with concentrations of 4, 12, 25, 50 and 70 mg per liter of phosphor prepared from phosphate diammonium salt [(NH4)2HPO4]. Freundlich sorption isotherms were used to evaluate the P requirement of 4 soils in a lab study. The soils were medium to heavy textured, alkaline in reaction and were highly calcareous. Results indicated that standard phosphorus requirement decreased from the 7.45 mg/kg to the 0.25 mg/kg and the average phosphorous adsorption by the soil samples was 2.82 mg/kg. There was a significant positive correlation between soil clay and organic matter contents and the quantity of phosphorus adsorbed by the soil so that phosphorous adsorption by the soil increased with increases in soil clay and organic matter contents.

کلیدواژه ها:

Freundlich sorption isotherms ، phosphorus ، Ttropical soil ، Aagriculture