INFLUENCE OF SILICON ON PHOSPHATE SORPTION IN BAJOA AND ISHURDI SOIL SERIES

The phosphate sorption capacities of the Bajoa and Ishurdi soil series were investigated, along with the influence of silicon on sorption and the evaluation of adsorption equations that best describe the relationship between solution P and adsorbed P.

The study revealed similar differences in the phosphate sorption capacities of the two soil series. Ishurdi soil demonstrated a higher sorption capacity than the Bajoa soil series, primarily due to its higher clay content, which plays a major role in phosphate sorption. Silicon application enhanced the phosphate sorption capacity in both soil series, with Ishurdi showing a higher increase than Bajoa. Phosphate sorption was gradually increased with increasing phosphate concentrations.

Among the three adsorption equations, the Langmuir equation provided the best fit for describing the phosphate sorption behavior of both soil series. Langmuir equations were able to explain the soils’ sorption maxima and binding strength. Both soil series with silicon application showed higher sorption capacity and increased P binding strength. The addition of silicon also elevated the phosphate buffering index, indicating more substantial resistance to changes in soil solution phosphate concentrations and suggesting the need for higher fertilizer application to ensure crop phosphorus availability. While phosphate binding strength increased in the Ishurdi soil series with silicon application, it decreased in the Bajoa series, reflecting the distinct soil properties and interactions. The maximum Phosphate buffering capacity (MPBC) increased in both soil series with silicon addition.

The findings align with insights into the complex interactions between silicon and phosphate in soil systems. The results imply that the application of silicon may inadvertently reduce the availability of phosphorus to plants by increasing its sorption and retention in soil. Consequently, these findings emphasize the need to carefully consider silicon amendments in phosphorus management strategies, particularly in soils with inherently high phosphate sorption capacities. 

• Supervision