What does one use to inoculate the root systems of trees?
There are four possible sources of mycorrhizal fungi, which use an ‘inoculum’ from: • topsoil containing fine roots, collected under trees of the particular species that are growing in natural forest, savanna or a well-established plantation; • nursery or container soil that has recently been used to grow that tree species; • spores or pieces of the fruiting bodies producing them, or cultures of kinds of fungi that have been shown to make effective ectomycorrhizas with the tree species. • soil cultures of an arbuscular mycorrhizal fungus. For instance, strains of Glomus are beginning to become available. Which source is the best? Source (1) is a useful starting point if thriving stands of the tree species are available; Source (2) is convenient if there is an existing nursery producing good plants; Source (3), where available, is likely to prove the best way of obtaining ectomycorrhizas that can improve tree establishment, reliably and substantially. Source (4) – simple methods have be
