Abstract:
Phosphorus fixation with different soil components is the main problem making it less available
to plants. To approximate this biological measure, a method comprising of Fe-Al-Zr mixed oxide
filled DMT was developed in this study. For this purpose, Fe-Al-Zr ternary mixed oxide
nanocomposite adsorbent with 60, 25 and 15 percentage composition of Fe, Al and Zr,
respectively, was synthesized via impregnation method. The as-synthesized adsorbent was
characterized by XRD, BET, SEM-EDX, FT-IR and FAAS analytical instruments. Its crystal size
and surface area were found to be 29.59 nm and 107.53 m
2
/g, respectively. The phosphate
desorption study was conducted using the method developed in this study from four soil samples
which received different P treatments (0, 50,100 and 150 mg kg-1
) for 28 days of desorption time
and the phosphate desorption from soil to plant was predicted. The results suggest that the
phosphorus treatment and desorption time had significant effect on the amount of desorbed
phosphorus from the soil samples. That means low (0.71-13.41 mg kg-1
) P was desorbed from
control and higher (1.87-27.84 mg kg-1
) P from 150 mg kg-1
P treated soil at all levels of
extraction time (1-28 days) for all soil samples. The rate of desorption of P through DMT was
found to be 0.0315 hr-1
and was low as compared to other findings which implies the soil
samples in this study were highly acidic and high phosphorus fixing soil. The physicochemical
properties like pH-KCl, Av.P, TP, FeDCB, MnDCB and FeAAO were highly correlated with desorbed phosphorus. Generally, the present study attempts to add insight on the potential of this method
for assessing phosphate desorption kinetics from acidic soil, relevant for agronomic and
environmental advising of phosphate fertilizer application and use.
