Really? I found quite a few picturesof orange, ammonium nitrate clouds on Google. It’s a great cover if that’s all they find in the soil later is fertilizer. ----
ammonium nitrate IS fertilizer - stable under normal circumstances, but when it explodes due to overheating, it produces NO2 as a byproduct, which produces the signature orange plume.
"Chemistry Behind Beirut Explosion" "...under normal conditions the fertilizer is inert. It will slowly decompose over time but can explode if it is set off by a fire, especially if poorly stored.
When energy is applied to ammonium nitrate, like from a fire, the molecule is no longer stable. Because ammonium nitrate contains nitrogen in two different oxidation states, an exothermic reaction occurs between the two nitrogen species: the nitrate acts as an oxidizer, while the ammonium acts as a reducing agent. If the reaction is completely clean, the only products are dinitrogen, water, and a little oxygen, but side products like NO2 are common. Because all the products are gaseous, there is a sudden, large increase in pressure that will then travel outwards at supersonic speeds, which is referred to as the detonation."