Abstract: Effective conservation of traditional crop varieties is the basis of the long-term utilization of agricultural biodiversity, and will be one of the essential factors for the sustainable development of agriculture. Due to the intensive production practices in modern agriculture, a great number of traditional crop varieties have been rapidly replaced by the improved high-yielding varieties, which has caused severe “genetic erosion” in the genepool of crop species, and significantly reduced genetic diversity of crop varieties. It is therefore essential to preserve the shrinking crop biodiversity before it is completely lost. On-farm conservation is an important and dynamic in situ conservation method that conserves crop varieties in agricultural ecosystems. On-farm conservation can be defined as the continued cultivation and management of a diverse set of crop populations by farmers in the agro-ecosystems where a crophas evolved, and it allows the evolution of conserved crop varieties to be continued in their original habitats. However, in spite of the increasing interests in this method and a relatively large number of research and case studies reported in this field, there has been no significant achievement for on-farm conservation and many questions remain unanswered: Is on-farm conservation practical and achievable? Can on-farm conservation actually be conducted in modern agriculture? Is on-farm conservation a trade-off with agricultural development? What are the scientific issues for on-farm conservation? What incentives can their be for farmers to conserve genetic diversity in their farming ecosystems? All these questions need to be addressed scientifically with satisfaction when conducting effective on-farm conservation. It is therefore necessary to have a better understanding of on-farm conservation, to study mechanisms and scientific basis of on-farm conservation, and to be innovative to open a new dimension for on-farm conservation action. The biodiverse deployment of rice varieties, mixed planting of modern hybrid rice with traditional rice varieties in Yunnan Province, not only provided an excellent method of controlling rice disease and increasing rice productivity, but also demonstrated a powerful model for conserving traditional rice varieties in an effective and sustainable way. This model of mixed planting of a diverse set of crop varieties links farmer's long term benefit, socioeconomic concerns, and the actual conditions of locally based agro ecosystems appropriately with conservation activities. This model of using biodiversity to preserve biodiversity of crop varieties is a long term approach that will be sustainable and beneficial to farmers whose general living standard will be raised. It might provide possible solution for on-farm conservation of traditional rice varieties in a feasible and sustainable way., and probably has potential for other crop species, too.

Key words: ants, community structure, species diversity, habitat, Qufu