Soil fungal distribution and functionality as affected by grazing and vegetation components of integrated crop–livestock agroecosystems

Integrated crop and livestock (ICL) agroecosystems are characterized by a mixture of perennial or annual vegetation grazed by livestock and annual harvested crops. Compared to annual crops, ICLs hold the potential to enhance soil organic matter (OM) inputs, carbon sequestration, nutrient cycling, and water conservation. Soil fungi play an essential role in the transformation of OM and nutrients and soil structure stabilization; however their specific role in OM transformations in ICL agroecosystems has not been studied. This study evaluated mycorrhizal and saprophytic fungal populations (via fatty acid methyl ester profiles; FAME) and saprophytic fungal functionality (via FungiLog analysis) under two ICL agroecosystems and a continuous cotton (Gossypium hirsutum L.) system in the Southern High Plains of the U.S. The first ICL system included non-irrigated perennial native grasses, an annual cotton and foxtail millet (Setaria italica) rotation and deficit-irrigated ‘WW-B. Dahl’ old wor