Elemental Analysis of Plants Cultivated in Saline Soil by Laser-Induced Breakdown Spectroscopy (LIBS)

Abstract

The production of crops and vegetables is largely affected by soil salinity which is a rising problem all over the world. The irrigation water and fertilizers are playing a vital role in increasing soil salinity. The elemental composition of the Aerva javanica plants grown in the salty area has been studied using laser-induced breakdown spectroscopy (LIBS). The soil, root, and shoot samples were collected from the Khewra Salt ranges, which is the world’s second-largest salt mine, located in the Punjab Province of Pakistan. This work aims to detect the major saline metals present in the plants grown in the salt-affected soil for which the electric field has been applied as an additional excitation source to enhance the emission signals using LIBS. Calibration-free LIBS has been applied to extract the concentration of soluble metals such as sodium, magnesium, and calcium in the root and shoot samples. The plasma temperature was determined using the Boltzmann plot method while the electron density was estimated from the Stark broadened profile of the calcium line at 616.12 nm.

Keywords:

• Laser-induced breakdown spectroscopy (LIBS)
• plant
• plasma parameters
• salinity
• signal enhancement

Acknowledgments

The authors are grateful to the Pakistan Academy of Science and Mirpur University of Science & Technology (MUST) for Research Support.