Fig. 5

Scanning transmission electron microscopy and electron energy loss spectroscopy (EELS) of leaf powder form foliar spray of PCS25 (pine wood, clay, and sand biochar extract at 1:25 dilution) treated lettuce plant. Micrographs were obtained from different ultra-thin sections of the same biochar particle from Fig. 4. a Transmission electron microscopy (TEM) high-angle annular dark field (HAADF) micrograph and EELS spectra of an ultra-thin section of the nanoscale agglomerate revealing its mineral compositions in their respective b EDS spectrum. c EELS spectrum of region 1 marked in a. d HAADF micrograph of cropped area in a and its representative e EDS spectrum. f N-EELS spectrum of the marked area in a. g HAADF image of EELS 2 marked in a. b EDS spectrum of g and its EELS spectrum is presented in i