The Impact of Individual, Population, and Species As Well As Fertilizer Regime on Turfgrass Microbial Community Structures.

Soil microorganisms play an important role in turfgrass performance. Understanding how microorganisms associate with different species and cultivars of turfgrass may provide researchers the ability to breed for turfgrass plants that form better mutualistic and beneficial relationships with soil microorganisms. Previous research in Poaceae has shown that plant genotype has the ability to influence the rhizosphere microbial community structure. The objectives of this study were to (1) determine if there are differences in bacterial soil microbial community structure based on turfgrass species; (2) identify differences in bacterial soil microbial community structure of turfgrasses based on nitrogen fertility regime; Soil samples were taken from mature turf plots that were maintained at 7.6 cm mowing height and fertilized annually at one of three nitrogen rates: 0 lb N yr-1, 1 lb N yr-1 applied in the fall; 2 lb N yr-1 split between spring and fall. These treatments were applied to the plots for four full growing seasons prior to sampling. A single entry of each species (Festuca trachyphylla, Agrostis capillaris, Deschampsia cespitosa, Koeleria macrantha, Lolium perenne, Poa pratensis) was sampled in the spring of 2015. For each sample, both rhizoplane and rhizosphere soil was removed and used for analysis. DNA was isolated and then sequenced using HiSeq Illumina using bacterial primers. Data was analyzed using WinSCP, Putty and Mothur. Results from this research will inform turfgrass researchers about the impacts of both plant genotype and nitrogen fertility regime on soil microbial communities.