Farmers' varieties (landraces) of crops in Vavilovian centers of genetic diversity like Ethiopia are important resources for global agriculture. Using time-tested experiential knowledge and keen observations, farmers husband crop diversity to meet varied economic and cultural needs in the region's rugged topography, where soil and climate are variable and often marginal. In situ conservation of this biodiversity on farms requires knowledge of ecological, environmental and human factors that maintain it. Both natural factors and farmers' selection criteria shape sorghum diversity at farm level. A survey of 300 randomly selected fields in the North Shewa and South Welo regions examined factors maintaining crop genetic diversity at the field level, including the influence of farmers' selection criteria, variation in classifying sorghum plants, folk taxonomy, and farmers' storability knowledge. The owner of each field was asked why he/she planted different species and varieties of crops and relationships between crop genetic diversity and human and natural selection factors were quantified. 

This study demonstrates that for sorghum farmers' varieties in Ethiopia, diversity increases with altitude, field size, and farmers' selection criteria, and that both inter-and intra-specific crop diversity decrease with distance from the homestead. Intraspecific variation accords closely with folk taxonomy and farmers' knowledge of storability predicts measured resistance to rice weevils (a storage pest). Thus, farmers' knowledge is critical to conserving and using crop genetic diversity. Moreover, IPM practices should incorporate farmer knowledge into new systems for protecting cereal crop genetic resources from storage pest infestation and for development of weevil-resistant varieties. Explicit value must be placed on sustaining crop genetic resources and the knowledge base of the traditional farmers: they go together. Policies should facilitate the retention of this valuable heritage and farmers should be supported in conserving the agroecosystems in which they grow the amazing diversity that we see today and to help them increase food production for the future without undermining genetic diversity. Farmers and scientists can and should work together in conserving agroecosystem biodiversity.  

Conserve Resources

Farmers in this system conserve genetic resources by maintaining local farmers' varieties.

Adjust to Local Environments

Farmer selection of locally-adapted farmer varieties adjusts crops to local environments.

Manage Ecological Relationships

Intensive intercropping of climbing beans, chickpea, sesame, safflower, teff, maize and sorghum, plants with complementary growth patterns in time and space, is used to manage weeds, reduce tillage, and increase total biomass harvest.

Diversify

Increased biodiversity is achieved by intercropping different species and different landraces of the same species, like sorghum.

Empower People

Maintaining crop genetic resources in situ enables farmers to control their genetic resources to address agricultural sustainability and food security at the community level while sustaining & valuing farmer knowledge.  

Related Publications:

Teshome, A., L. Fahrig, J.K. Torrance, J.D. Lambert, T.J. Arnason, and B.R. Baum. 1999. Maintenance of Sorghum (Sorghum bicolor, Poaceae) landrace diversity by farmers' selection in Ethiopia. Economic Botany 53:79-88.

Teshome, A., J.K. Torrance, B. Baum, L. Fahrig, J.D.H. Lambert, and J.T. Arnason. 1999. Traditional farmers' knowledge of sorghum (Sorghum bicolor (Poaceae)) landrace storability in Ethiopia. Economic Botany 53:69-78.