Kinetics of phosphorus desorption from soils using a modified DMT-HFAO technique and its relationship with phosphorus fractions and maize (Zea mays L.) yield

Abstract

This research investigated the kinetics of phosphorus (P) release from soils by employing an improved technique-hydrous ferric aluminium binary oxide in dialysis membrane tubes (DMT-HFAO). The as-synthesized adsorbents were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared (FTIR), thermogravimetic (TGA/DTA) and Brunauer-Emmett-Teller (BET) techniques. The modified method, DMT-HFAO, was used in six soils equilibrated for a period from 1 to 42 days. Two component first order model was applied to estimate the cumulative P desorbed and P desorption indices and how these parameters are related to maize yield. The cumulative P-extracted by DMT-HFAO over 42 days significantly correlated (p < 0.01) with maize plant uptake; better than the reference single system (DMT-HFO). This indicated that DMT-HFAO is superior in mimicking plant mode of action as compared to the benchmark, DMT-HFO. Among the P fractions, HCO3-Pi, HCO3-Po and D/HCl significantly correlated with the yield parameters in both techniques. Our findings, therefore, provide some insights on the importance of this modified technique in estimating the residual P in soil. Accurate estimation of residual P is important not only from environmental perspective but also from the judicious use of this non-renewable fertilizer.

Keywords

• Phosphate
• Desorption
• Binary oxides
• Nanosorbent
• Dialysis membrane tubes