Adsorption Behaviour and Microstructural Study of Non-Polar Amino Acids in Natural Soil Amended with Pesticide

The aim of the present work is to understand the complex relationship between amino acids including glycine, alanine, 2-aminobutyric acid, leucine and methionine in natural soil and soil amended with pesticide. Soil samples were characterized using scanning electron microscopy (SEM) and X-ray diffraction technique (XRD). The soil thin layer chromatography method was used to study the adsorption behaviour and mobility of amino acids on natural soil and in soil amended with chlorpyrifos. Results found that the overall percentage change in Rf values from sample without chlorpyrifos and sample with 8 % chlorpyrifos is 37.5% for glycine (lowest molecular weight) and 10% for methionine (highest molecular weight). However, for the rest of the three amino acids, it was in the range of 14-15%. Chlorpyrifos is found to decrease the mobility of five amino acids in soil by making them more adsorbed on soil surface. Adsorption of amino acids is a key contributor for plant nutrition. In the present study, lowest mobility was found for glycine in pure soil and in soil amended with chlorpyrifos indicating maximum adsorption on soil surface. In future studies, adsorption performance of amino acids on soil can be analysed in presence of various additives. Keeping in view the significant effects of amino acids and pesticides on soil and plant health, it is estimated that this technology can be applied for further investigation in different fields of soil engineering.