Comparison of Highly Managed Winter Wheat Soils to Improved and Tallgrass Prairie Pastures on Soil Microbial Community Structure Using PLFA.

Cropping system management can greatly alter soil nutrient cycling and has been studied thoroughly. However, soil microbes are responsible for much of the soil nutrient cycling and are noted also to be effected by management practices. In the Southern Plains annual winter wheat (Triticum aestivum) and perennial pastures are dominant to support cattle forage needs. Over 2015-2017 monitoring of seasonal microbial community dynamics in these management systems. A management gradient was established from minimal inputs in a tallgrass prairie system, improved pasture to annual winter wheat. Soil was collected and analyzed for microbial community structure using polylipid fatty acid profiling (PLFA), three times a year given vegetation growth stages. Early in the growing season soil microbial communities were dominated by bacteria in the annual cropped soils and had a mix of microbial groups in the improved pasture, with greatest diversity in the tallgrass prairie soils. At peak growth soils were equally dominated by bacteria and actinomycetes in the annual and improved pastures with tallgrass prairie continuing to have a mix of groups. Post harvest analysis indicated that microbes such as bacteria were less prevalent and fungi were dominating.