Improving soil fertility and soil functioning in cover cropped agroecosystems with symbiotic microbes

Abstract

Cover cropping with graminoids or legumes represents an important strategy in agricultural production systems for the improvement of soil fertility and soil functioning. The organic carbon derived from both aboveground littering and root deposition of cover crops can greatly regulate the functional microbial groups involved in the substance cycling of nitrogen, carbon, and phosphorus. This regulation normally improves soil quality from a long-term perspective, and the effects can vary much depending on cover crop species or soil types. On the other hand, symbiotic microbes, such as arbuscular mycorrhizal fungi and rhizobia, can bring great benefits to cover crops and the associated soils. They regulate the soil fertility and soil functioning via the direct effects on native soil microbial communities or the indirect effects through altered plant growth of cover crops. Recently, the synergic effects of cover crops and symbiotic microbes are explored, and the combination of cover cropping and symbiotic microbial inoculation is emerging as a potential technology for sustainable agriculture, mainly in the horticulture area. This chapter reviews the recent progresses in the improvement of soil fertility and soil functioning with cover crops via the soil functional microbial groups, with special focus on the addictive effects of symbiotic microbes.