He admitted possessing sulphur powder and potassium nitrate and a book on Semtex.

BBC: Terror charges boy aged 16 pleads guilty

Current molten salt mixes are typically 60% sodium nitrate and 40% potassium nitrate.

FORBES: Secret Ingredient To Making Solar Energy Work: Salt

Police had found a large quantity of potassium nitrate, sulphur, five metres of cable, alarm clocks, headlamp bulbs and a pressure cooker that could serve as a bomb casing.

BBC: France 'uncovers biggest bomb plot in years'

And David Laird, of America's Department of Agriculture, showed that biochar even helped the rich soil of America's Midwest by reducing the leaching from it of a number of nutrients, including nitrate, phosphate and potassium.

ECONOMIST: Biochar could enrich soils and cut greenhouse gases as well