Effect of agricultural practices on mycorrhizal diversity and abundance in winter wheat fields of Khorasan province

As a part of soil biodiversity, mycorrhiza has an important role on soil function. For assessment of agricultural practices on spore density and diversity of mycorrhiza, a study was conducted in winter wheat fields on Shirvan, Mashhad and Gonabad, three regions of Khorasan. In each region, high and low input fields of winter wheat and a natural system for comparison were selected. Use of agricultural inputs was criteria for selection of low and high input fields in each region. Soil sampling was done on fields and natural systems. Organic matter and spore density of mycorrhiza were measured in soil samples. Percent of soil organic matter in all systems was low, but in agroecosystems was greater than in natural system. Mean spore density of mycorrhiza in the soil of Shirvan, Mashhad and Gonabad was 118, 99 and 76 per gram dry soil, respectively and was affected by region and soil organic matter. Soil spore density in agroecosystems was greater than natural systems and was affected by soil organic matter and plant production. Species richness of mycorrhiza in high input and natural systems of Gonabad was 4 and in other systems were 5. Results showed that agroecosystems improved conditions for mycorrhiza and efficient use of these services.