The Department of Land Development, which deals with
agricultural land development, recommends that farmers
living on slopes with grades between 12% and 35%
construct bench terraces or hillside ditches combined with
buffer strips of vegetation such as vetiver (Vetiveria
zizanioides) or napier grass (Pennisetum purpureum)
(Attaviroj, 1996) to control erosion. While terrace paddy
cultivation is traditional for some ethnic groups in Thailand,
using such techniques for upland crops is new, and most
farmers are not familiar with soil and water conservation
practices for terraces for upland crops.