Soil Characteristics for Tuber magnatum

Tuber magnatum (the Italian white truffle) is closely related to the soil environment and can be found in well-drained soils without gravels, having a neutral to moderately alkaline pH, a high degree of base saturation and enough water all over the year. Further peculiar soil characteristics for its growth are the lack of water stagnation in the surface layers, a very soft consistency and more than 15 % of the soil volume occupied by interconnected macropores. This combination of characteristics is fulfilled only in floodplains and hillslopes where geomorphic processes rejuvenate soils, originating a disordered distribution of particles due to frequent depositions of alluvial materials or to accumulation of soil aggregates transported along slopes by mass movement. These geomorphic conditions are also essential for the soil water regime of truffle grounds and their capability to sustain dense tree canopy cover, thus originating the cool environment required by T. magnatum. Soil suitable for T. magnatum mainly belongs to Calcaric Fluvisols, Colluvic Calcaric Regosols and Fluvic Eutric Cambisols. However, limited changes in adjacent soils influenced by the same soil-forming processes drastically decrease the probability of finding T. magnatum ascomata.