Anderson: Plants and people of the Golden Triangle - Ethnobotany of the hill tribes of northern Thailand
A detailed study of plant use and agriculture of the so-called hill tribes of Thailand that equally applies to the traditional farming techniques of Yunnan's minorities, well illustrated.
Dioscorides Press
1993, ISBN 0931146259
Related Reading
Ethnobotany
Arguably, man-kind has survived much longer with gathering and swidden agriculture than it will using modern intensive industrialized farming. The books in this list go to the roots of indigenous knowledge in plant-use and hill farming. Plus one of the books tells you the mystery why hill-farmers need to understand prime numbers.