Yes, it felt strange to think of the Karen as horticulturalists, being predominantly rice farmers (for some reason I picture horticulturalists more as veg and root-crop growers) but they fit the definition… It didn’t occur to me that you could farm grains as part of a rotational system, rather than insisting on their continued cultivation on the same piece of land year after year. On the sustainability question, the main claim in the article related to soil erosion:
The results of research conducted by Chanpen Chutima Teewin of the impacts of the Karen people's rice cultivation method on soil surface showed that the rotational farming system of the Karen currently causes soil erosion below the accepted standard level (0.2 tonnes/rai/year). The study stated that the rice cultivation method of the Karen and Lua peoples uses the land in a manner which does not cause soil erosion, and that this was achieved by growing plants that do not disturb the soil, by digging holes to plant seeds, and by growing a variety of plants, such as fertilizing plants and ground-cover plants. This cultivation method is effective in lowering and preventing soil erosion in highland areas. Chanpen's study states that of ten areas studied, six areas had soil erosion that did not exceed the accepted standard, and four areas had very little soil erosion.
I suppose 0.2 tonnes/rai/year still represents some soil erosion, even at a small rate, but probably the other plant communities that come in during the fallow years build up the soil to compensate, so the overall effect might be to build topsoil rather than strip it away totally. Impressive for hill farming! By contrast the ‘type 4’ rice farming of ‘Long cultivation-very long fallow or abandonment’ seems to support clicketyclack’s point about sedentary vs. nomadic people:
With the exception of the fourth type, the practice of these farming models require the farmers to establish permanent settlements.
Makes sense really - if your food-growing system depletes the soil beyond repair you have to move on once it’s exhausted. Agriculturalists as the true nomads, who’d-a thought it!
Interesting question - fire is obviously also a source of ‘catastrophe’. The only major differences I can think of at the moment are that, unlike plough cultivation, fire doesn’t disturb the soil in the same way (perhaps the microbial/fungal life would survive a light burn? - I don’t know), and it doesn’t totally reset the ecological clock because the big trees are left (in the oak system at least).
Will check out that new ag stuff in a bit. Looks v. interesting at first glance!