Mycorrhizal Colonization of Cranberry: Effects of Cultivar, Soil Type, and Leaf Litter Composition

Although ericoid mycorrhizal fungi improve nitrogen (N) nutrition of cranberry ( Vaccinium macrocarpon Ait.) and other Ericaceae in their native habitat, the prevalence of ericoid mycorrhizal colonization in cranberry has not been widely examined. The authors measured ericoid mycorrhizal colonization of cranberry root samples from 13 cultivars growing in cranberry beds in Wisconsin. Mycorrhizal colonization was present in all samples. Bed age had a slight but statistically significant negative effect on mycorrhizal colonization. Neither cultivar, bed substratum, nor soil pH had a significant effect on mycorrhizal colonization. Fungicide treatment for fruit diseases did not appear to affect mycorrhizal colonization of cranberry roots. Soil layering in the root zone incited by regular sanding had a significant effect on mycorrhizal colonization; colonization decreased with increasing depth in the root zone soil. Leaf litter was more decomposed in deeper soil layers, with a lower carbon-to-N ratio. Given the consistent presence of ericoid mycorrhizal fungi in cultivated cranberry, it is possible that they may play a role in N nutrition of the cranberry agroecosystem.