Ecological studies on the transition from shifting cultivation to continuous upland farming in northern Thailand, 3: Crop root systems under mono-cropping and intercropping conditions in a slash and burn field

burning campo champ continuous cropping cultivo continuo cultivo intercalado cultivo migratorio cultivos de secano culture continue culture de moyenne altitude culture intercalaire fields intercropping quema restos de corta root systems shifting cultivation sistema radicular slash tailandia thailand upland crops