Increasing Plant Mycorrhizal Status and Improving Soil Properties with Cover Crops.

Mycorrhiza are the most common mutualistic symbiosis between fungi and plant roots. Benefits of mycorrhizal fungi to plants are to increase growth and productivity of the plants by increasing uptake of nutrients and water. In return, the host plant provides carbohydrate (energy) to the fungi. Agricultural management practices such as tillage, cover crops and crop rotation effect the distribution and abundance of arbuscular mycorrhizal fungi (AMF) in soil. Cover crops provide benefits such as: protect soil from erosion (wind and water), reduce weed growth, increase soil organic matter, improve soil properties, and increase biomass and diversity of mycorrhizal fungi and other soil microorganisms. In this study, we aimed to assess the influence of a cover crop on arbuscular mycorrhizal fungi biomass in soil, AMF inoculum potential, soil aggregation, and soil organic carbon. A field experiment was conducted in five agricultural fields of Bighorn Basin, Wyoming with different periods of cover crops between 0-3 years. The result demonstrated that the fields with cover crops had higher concentration of AMF biomarker phospholipid fatty acids in soil compared with fields without cover crops. There were no significant difference in the proportion of macroaggregates and microaggregates between the fields containing cover crop and non-cover crops. There were strong relationships between AMF biomarker PLFA and macroaggregates and microaggregates suggesting that the increasing biomass of arbuscular mycorrhizal fungi can help to increase the proportion of macroaggregates and microaggregates. Cover crops facilitate biomass production by AMF in soil and improvement of soil properties, both of which increase profitability and sustainability of agricultural systems.