Thanks
Yes, the routine was to drill stumps, fill the holes and cover with a piece of slate or even plug the hole with clay if any was to hand. It took weeks to move through the stump, but what I was told was that eventually you could light the wood and it would smoulder gently for as long as it took to burn most of the stump out if you'd used enough oxidant and given it enough time. It was something like 35 years ago, so details of timing etc. are long forgotten.
Potassium nitrate is an obvious choice, even mentioned elsewhere online, but I want the stump to smoulder, burn slowly. I'd want comment from someone who has actually used the method.
Searching more online, ammonium carbamate is actually a fire supressant in some formulations. Both the carbamate and nitrate are compost accelerators as they provide nitrogen, as does urea, as the huge majority of compost heaps are defficient in nitrogen for bacteria to work as fast as they otherwise might.
I can't find any mention of carbamate being used as a herbicide/arboricide.
The carbamate would be exceedingly environmentally friendly as it readily decomposes to a mixture of ammonia, carbon dioxide and carbonates, so why it might be banned when the nitrate is not (it is actually an exceedingly common agricultural fertiliser).......
A very quick check on EPay and sodium chlorate isn't available, no surprise. Potassium nitrate very much is as it has uses in food prep', such as curing meats.
