Weed Control Fields are ploughed approximately fifteen days before planting in the belief that exposure to the sun will kill the weeds. During interculture operations, manual weeding is carried out, burning is still prevalent. On rainfed Khet , flooding through irrigation is carried out to effect weed control. Soil Fertility Practices Management practices indicate that the farmers' knowledge extends to the biological relations between crops and other natural resources. They are able to match soil conditions to requirements of the crops by observing certain indicator plants, e.g., ferns.
Edible ferns are found only on fertile soil, unedible ferns indicate the opposite condition.
The two basic types of soil fertility maintenance are manuring and management. Sources of animal protein found in these systems, such as frogs, are eaten. Other practices involve ploughing in weeds in situ, intercropping cereals and legumes, high seedrate practices in rainfed conditions, and maintaining moisture. Grass is burned before the rains to enhance fertility levels through the release of nutrients. Indigenous Knowledge and Natural Resources' Management In Yunnan Province, China Two communities in Zixishan, China, namely the Zyin and Zunging, inhabit a sacred religious site that is also a nature reserve in Chuxiong, Yunnan Province.