Comprehensive elemental and carbon profiling of Punjab’s soils: distribution patterns, pollution assessment, and source attribution

Soil analysis is a critical tool for optimizing crop production, managing soil nutrients, preventing environmental degradation, and making informed decisions about land use and agricultural practices. This study focuses on optimizing the energy dispersive X-ray fluorescence (EDXRF) parameters for the analysis of 22 elements in soil samples collected from Punjab, India. The reported elements in the soil were classified into three categories based on their abundance: major (Al, Fe, K, Mg), minor (Ba, Mn, Zr, Rb, Ce, Sr, Cr, and V), and trace (Zn, Ni, Pb, Cu, As, Sc, Co, Br, Cs, U). Their occurrence in the soil samples is discussed. To assess the level of soil pollution with toxic elements and the anthropogenic input, the study calculated and discussed various indices, including the contamination factor, index of geoaccumulation, and pollution load index. The results indicate that As and Pb are the most contaminating elements in the soil based on the calculated pollution indices. The average pollution load index (PLI) value for soil samples collected from Punjab is 1.14, indicating slight pollution relative to the Earth's crust. Principal component analysis (PCA) of the data indicated both natural and anthropogenic sources of elements in the soil from the study area.