Phosphorus Desorption Study Using Dialysis Membrane Tube Filling Fe-Al-Mn Ternary Mixed Nanocomposite from Different Farming Practice of Acidic Soil

Abstract

Knowledge of the effect of the P remaining in the soil (residual effect) is of great importance for fertilization recommendation. Environmental applications of nanotechnology address the development of solutions to the existing environmental problems, preventive measures for future problems resulting from the interactions of materials with the environment. For this purpose, Fe-Al-Mn ternary mixed oxide nanocomposite adsorbent with 70, 25 and 5 percentage composition of Fe, Al, Mn respectively was synthesized by impregnation method. Its crystal structure was hematite with 20.31 nm size and 69.93 m²/g surface area. The study of phosphate desorption was carried out on different farming practices with four types of treatments: Sole Maize conventional practice (SMCP), Sole Maize conservational agriculture (SMCA), Sole Haricot bean conservation agriculture (SHCA) and Maize-Haricot bean intercropping conservation agriculture (MHCA). The simulation of phosphate desorption from soil to plant was predicted by dialysis membrane tube filled with the ternary mixed nanocomposite (DMT-FeAlMn). DMT-FeAlMn was founded to be the promising adsorbent to simulate the plant–phosphate relation in acidic soil or to estimate the properties of soil for phosphate desorption to the soil solution. The observed desorbed of phosphate was significant in the treatment order of SMCP < SHCA < SMCA < MHCA. The releasing rate of phosphate from soil followed first order kinetics having SMCP (R² = 0. 996), SMCA (R² = 0.997), SHCA (R² = 0.993), and MHCA (R² = 0.991) with rate constant 0.0006hr^-1_.

Keywords: Desorption, Nanosized Fe-Al-Mn mixed oxide, Residual soil-phosphate, Farming practice