Die Bodenkultur - Journal for Land Management, Food and Environment

F.-G. Loth:

Abundance of arbuscular mycorrhizal fungi spores at different native sites in dependence on sewage sludge applications

Summary

Soil samples of different soils from eleven native sites in Hesse (Germany) with and without sewage sludge treatments were collected. The soils were examined for heavy metal contents and additionally for spore density of arbuscular mycorrhizal fungi. The sludge applications increased the EDTA-soluble heavy metal contents in most soils and predominantly in the case of Zn. The differences of metal concentrations between the sites were greater than the variations found from sludge application. Populations of the endophytes in the soils were rather high with spore densities of 31 to 97 per gram of dry soil. The effect of sludge on the population of spores differed between the habitats. The significant correlations between the density of spores and the organic matter (r= 0,72) partly explained the higher degree of soilborne endophytes in some sludge treated soils. At some locations, decreasing mycorrhiza populations occured with sludge fertilisation. A possible explanation could be the higher sensitivity of mycorrhiza fungi to heavy metal contents and especially to Zn. The differential results shows specific ecological adaptation of mycorrhizal populations. Key words: arbuscular mycorrhiza, populations of spores, sewage sludge applications, heavy metals.