Arbuscular Mycorrhizal Fungi Communities in Major Intensive North American Grain Productions

Abstract

With population increase, urban sprawl on some of the best agricultural soils and the interest for biofuels, serious pressures have been created on grain and oilseeds production in North America. Fertilizers are the main expense in intensive agricultural management practices. P fertilization is often closely related with soil degradation and contamination of surface water, causing eutrophication and accumulation of blue-green algae in certain locations of Canada. Arbuscular mycorrhizal (AM) symbioses have been shown to benefit plant growth in large part due to the very extensive hyphal network development in soil, exploiting nutrients more efficiently and improving plant uptake. AM symbiosis also increases resistance to stress and reduces disease incidence, representing a key solution in sustainable agriculture. Appropriate management of mycorrhizae in agriculture should allow a substantial reduction in chemical use and production costs. This chapter will review the effects of various fertilization practices on AMF community structure and crop productivity in major North American grain productions (i.e., corn, soybean, wheat, barley), and their reaction to other common management practices (i.e., tillage, rotation, pesticide use).