Influence of different soil types on abundance and seasonal dynamics of vesicular arbuscular mycorrhizal fungi in arable soils of North Germany

Summary. The present investigation examines whether characteristic mycorrhiza occur in intensively used agricultural soils of different types. For this purpose, three arable soils in the north of Germany were chosen and the formation of mycorrhiza, spore density and the frequency of spore types within populations were investigated over two cultivation periods (1986/1987 and 1987/1988). Soil type influenced spore density as well as the percentage of mycorrhizal colonization of roots during each cultivation period, whereby high spore density was not necessarily connected with intensive mycorrhizal development. Although the level of mycorrhizal colonization increased most rapidly in silty sand, the highest level of infection was observed in barley roots in clayey soil. At harvest, infection levels differed in the soils investigated, but spore density was equal at all three sites. Each soil type displayed a characteristic distribution of spore types within a population; this distribution remained unchanged over the two cultivation periods.