A recently harvested upland rice field, Ban Cha Wang, Phongsaly province, Lao PDR. Slash and burn cultivation or ‘hai’ in Lao consists of cutting the natural vegetation, leaving it to dry and then burning it for temporary cropping of the land, the ash acting as a natural fertiliser. Shifting cultivation practices, although remarkably sustainable and adapted to their environment in the past, have come under increasing stress in recent decades and are now starting to be a major problem in Lao PDR, causing widespread deforestation and watershed degradation.