Assessing the fertilizer and pesticide input needs of cool-season turfgrass species

Professional turfgrass managers and consumers continue to express interest in low-input turfgrasses; however, the potential reductions in maintenance inputs from "low-input" turfgrasses are largely assumed and have not been well-quantified. Over 3 years, replicated field experiments at Purdue University and the University of Minnesota quantified the performance and the amount of fertilizer and pesticide inputs of cool-season turfgrass species when managed as variable-input turfgrass systems. Fifteen turfgrass cultivars including eight cultivars across five taxa of fine fescue (Festuca spp.), two cultivars of tall fescue (Festuca arundinacea), four cultivars of Kentucky bluegrass (Poa pratensis), and one perennial ryegrass (Lolium perenne) cultivar were investigated. Cultivars were selected to represent advances in breeding efforts. Plots received no irrigation after establishment and individual plots only received fertilizer or pesticide inputs from 2019 to 2021 if the turf in the plot exceeded or fell below a set threshold (i.e., too many pests or too low turf density). Monthly data collection and fertilizer and pesticide inputs were recorded for 3 years at each site. New fine fescue taxa cultivars provided consistently higher turf quality at both sites and required an average 56% and 41% fewer fertilizer and pesticide inputs than traditional species (tall fescue, Kentucky bluegrass, and perennial ryegrass) in Indiana and Minnesota, respectively. Compared to traditional species, older Festuca rubra ssp. cultivars reduced fertilizer and pesticide inputs by an average of 37% and 25% in Indiana and Minnesota, respectively. Fine fescue taxa, especially new cultivars, are good choices to reduce inputs and provide high turf quality for low-input turfgrass systems.