ABSTRACT
Despite recent efforts to qualify and quantify the impacts on agricultural practices on biological indicators of soil quality (for a review, see Doran and Zeiss, 2000), we know surprisingly very little regarding the impacts to soil fungal communities. One exception may be the arbuscular mycorrhizal (AM) fungi, where their responses to agricultural stresses and their contributions to soil conservation and crop productivity have been relatively well studied and reviewed (Bethlenfalvay, 1992; Johnson and Pfleger, 1992; Miller and Jastrow, 1992, 2000). In general, however, soil fungal
communities
are understudied in agricultural sciences. In the previous edition to this book, only a handful of studies were
presented in the brief section describing soil fungal responses to agroecosystem disturbances. There, Zak (1992) presented cases where tillage and monocropping reduced fungal species richness and altered the species composition of the fungal community, but the effects on fungal activities such as nutrient cycling and organic matter accumulation were largely unknown at the time. In a more recent review, Miller and Lodge (1997) summarized effects of tillage and crop rotations on soil fungi, with an emphasis on pathogenic and mycorrhizal populations. They also outlined several significant functional roles of soil fungi in agroecosystems, namely, stable aggregate formation and nutrient cycling, and thereby illuminated the importance of fungi to the stability of agroecosystems.
