Ecological Study on Symbiotic Status of Arbuscular Mycorrhizal Fungi in Agricultural and Rangeland Ecosystems (Case Study: Sarab Region, East Azerbaijan Province)

Sustainable agriculture is achievable by establishing a balance between plant and soil, and depends on the ability of soil and plant to support native and diverse microorganisms such as mycorrhizal fungi. These fungi by increasing the growth of the host plant and the development and stimulation of root secretions especially glomalin, plays an important role in considerable stability in soil ecosystem. Changing rangelands to agricultural uses can affect the symbiosis of these fungi and endanger the stability of ecosystems. This study was conducted in an area of 310 km2 in Sarab plain, The wheat, alfalfa, and potato fields were considered as agricultural uses of neighboring rangelands as control soils. From each land use, 30 samples were taken from the rhizosphere soil and roots of the plants and a total of 120 samples were taken. The percentage of mycorrhizal colonization and the amount of root glomalin and some soil properties were measured.

The root colonization was the highest in alfalfa compared to other land uses. Root glomalin was not statistically different between land uses. Soil available phosphorus had positive effect on root colonization at lower content (< 50 mg kg-1) while colonization percent showed a marked decrease above this level.

Colonization of perennial plants was more than annual plants and available phosphorus was the most important soil property that had an effect on fungal colonization of plant roots. However, no significant relationship was observed between contents of root glomalin and soil available phosphorus in different land uses.