Abstract:
An ecogeographic survey was conducted in six key agricultural zones in Morocco to study the abundance and the relationship between the natural distribution of annual Trifolium species and environmental factors. Sixteen species of annual Trifolium species were identified. Most prolific was T. scabrum and the least were T. striatum and T. bocconei. Fifty-five percent of the sites had no Trifolium and the average number of species per site was 2.2. An average seed yield of 4.8 kg ha-1 was obtained. Both soil and climatic factors affected the occurrence of Trifolium species. Rainfall, pH and phosphorus content were the most determinant factors affecting the distribution of Trifolium species in Morocco.