At present, farming_system is used in Nepal to mark bari and khet , referring to specific farming practices in the area. I am proposing to use this tag with jhum to mark farmland in NE India / Myanmar where traditional jhum shifting cultivation (slash-and-burn farming) is practiced.

These are fields which are essentially permanent farmland, but which are left to re-wild for some years before being used again. Contrary to some beliefs about the method, the entirety of the jungle is not used for this type of farming. Instead, it is always the same fields that the communities cycle between.

Expansion of this tag to include jhum could enable greater tracking of such fields as part of ongoing scientific analyses of this methods of farming and their impact on the environment. Use of the farming_system tag does not affect rendering, or interfere with any other tags. As farming_system is already in wide use in Nepal but otherwise unused, it is the ideal option for tagging jhum land use.

edit: Discussion on the tagging forum here: https://community.openstreetmap.org/t/proposal-for-farming-system-jhum/106877/4