Spectral changes in the leaves of barley plant due to phytoremediation of metals—results from a pot study

Abstract

This research studied the changes in leaf reflectance spectra (350–2500 nm) due to metal phytoextraction into barley plants grown in metal-spiked soils (3 levels of Cd, Pb, As and their metal-mixture treatments). Growth of barley was adversely affected due to 100 mg As kg^-1 and metal-mixture (10 Cd+150 Pb+100 As; mg kg^-1) treatments. Metal phytoextraction were in order of: root>straw≥leaves >grains. Results of reflectance spectra of leaves show the influence of As-treatment only, causing spectral changes in visible and infrared domains mostly, as apparent from the significant correlation between leaf-As and leaf-spectra. Chlorophyll and water stress indices and band depths analyses showed significant correlations to leaf-As, and can be used to distinguish metal-stressed plants. Finally, regression models demonstrate the potential use of hyperspectral reflectance data to monitor plant health during phytoremediation process and to estimate leaf-As in barley, particularly in this study.

Keywords:

• Phytoextraction
• metal-contamination
• barley
• spectral reflectance
• vegetation indices
• regression analysis