Assessment of tillage erosion rates on steep slopes in northern Laos

In most tropical areas, the increasing weed pressure resulting from the intensification of upland farming requires farmers to dedicate more labour to weeding (Nye and Greenland, 1960; Roderet al., 1995). In the highlands of Thailand, Laos and Vietnam,shifting cultivation is still a dominant feature of subsistence farming but the system has become increasingly distorted in response to population pressure, inappropriate techniques, but also peculiarly in Laos, to resettlement (Lestrelin et al., 2005).