Agro-environmental sustainability of the Yuanyang rice terraces of Yunnan (China): lessons for Europe.

Abstract

The Hani minority people of Yunnan Province (south-west China) have developed a complex and sustainable agro-environmental system of terraced rice paddy fields in Yuanyang (22°49’-23°19’N, 102°27-103°13’E). The Hani people have maintained this intricate and elaborate system for over 1500 years, with some 3,000 terraces covering about 11,000 hectares. Hence, during the Ming Dynasty (1368-1644), the Emperor awarded the Hani people the title of ‘Magic Mountain Sculptors.’ However, geographic isolation and proximity to the, until recently, politically-sensitive border with Vietnam, has meant the Yuanyang terraces have attracted scant scientific attention. If we can understand how this system is sustained, we can learn lessons which hopefully can be applied more generally. The sustainability of the system seems to be the result of complex interplays between cultural, agronomic and environmental factors. These include the cultural and spiritual beliefs of the Hani people, a hydrogeological system which provides ample water resources, the maintenance of genetic diversity within the dominant rice cropping agro-ecosystem and the operation of complex fertigation practises. Distilling and understanding the ‘secrets’ of the Hani people and their terraces should enable broader application and dissemination of the principles of sustainability. Currently a joint Chinese-European team are working towards a greater understanding of these lessons. The research team postulate that these lessons will have some applicability for agro-environmental sustainability in Europe. Identified lessons relate to resource optimization, landscape multifunctionality and cultural attitudes. Landuse within Yuanyang is zoned on the basis of ecological principles. Upland grassland progresses downslope into forest and then in a downslope sequence into tea plantations, bamboo woodland and rice terraces. Grasslands are used for the grazing of water buffalo, while wooded areas provide timber (deciduous, pine and bamboo) and food (mushrooms, wild vegetables and honey). The local Yunnan pine (Pinus yunnanensis) provides an excellent source of timber. Furthermore, the forest is very effective in conserving soil and water and releases high quality water from the upper to lower slopes. Besides providing rice, the perennially wet paddy fields provide food for domestic consumption (carp, eels, mudfish, ducks, frogs and snails) and weeds for pig-feed. Thus, there is multifunctional use of each eco-agricultural zone, which ensures optimum use of resources, effective recycling of materials and minimal waste. Often, the net waste from these subsystems is virtually zero. The Hani people have a unique cultural system that reveres the land. The Hani religion embraces polytheism and the worship of nature. They pay particular devotion to the ‘forest god,’ which is perceived as the source of life-giving water. Deforestation is considered a religious violation and the Hani people actively teach their children to respect the forest. This concept significantly contributes to forest conservation and ecosystem stability. In Europe, we can learn much from these positive environmental attitudes, in terms of improving public understanding and appreciation of land resources (land literacy) and agro-environmental education at multiple levels (school, college and university)