Effects of soil depth and characteristics on phosphorus adsorption isotherms of different land utilization types Phosphorus adsorption isotherms of soil

Phosphorus (P) is an indispensable natural mineral for biological processes and structures that support life in plants and animals. P deficiency is the most common nutritional stress of cultivated land in many regions of the world. The aim of this study was to determine the phosphorus (P) sorption characteristics of some soils and derive parameter estimates relevant in the prediction and management of P as well as their relationship to the properties of the soils. Four soil samples (each taken from depths of 0-10, 10-20 and 20-30 cm) were obtained from the Eastern Region of Ghana for this study. An uncultivated virgin land at Huhunya (HV), a cocoa farm in Akwadum (AC), a plantain farm also in Huhunya (HP) and piece of land which had been allowed to go fallow in Huhunya (HF) was used. Measurement of P sorption was conducted by equilibrating air-dried soil (<2 mm) in 0.2 M CaCl2 solution containing various concentrations of P. Phosphorus sorption data for soils was fitted to the Langmuir, Freundlich and Temkin isotherm equations. The result of the study show that the amount of phosphorus adsorbed increased with increasing depth with AC soil recording an average range of 114.16-211.55 mu g/ g. Phosphate adsorption was well described by the three isotherm equations. The data from the soils did conform best to the Langmuir equation with an average r2 value of 0.99. It was realized that virgin soil (from Huhunya) would require the most P fertilizer. The least P fertilizer would be required by the soil from the plantain farm (HP). Correlation analysis showed a significant relationship between some soil characteristics and the sorption parameters derived from the three equations.

Automated summary

Phosphorus (P) is an essential natural mineral for biological processes and structures that support life in plants and animals. This study aimed to determine the phosphorus (P) sorption characteristics of some soils and derive relevant parameter estimates for predicting and managing phosphorus as well as understanding their relationship with soil properties. The results showed that the amount of phosphorus adsorbed increased with depth, with different soils requiring varying levels of P fertilizer. Correlation analysis revealed significant relationships between soil characteristics and sorption parameters.