FUNCTIONAL TURFGRASS PERFORMANCE WITH REDUCED RESOURCE INPUT

Victor A. Gibeault, J. Michael Henry and Richard Autio

In many functional and aesthetic uses of turfgrasses, the possibility exists for grasses to be used that can adequately perform with lower inputs of resources and cultural practices than that of recreational or high-end aesthetic turfed sites. Examples are industrial, municipal, and many residential lawns, as well as lawns used in cemeteries and other facilities where traffic is not an issue. Such uses of turfgrass require a soil covered by a mowed uniform grass surface to give the functional and aesthetic results that are desired by the California urban/suburban population. Turfgrasses that perform at acceptable levels with low to moderate input of water, nutrients, energy, pest control and maintenance costs may be practical and desirable. These are important considerations given the strain on most public and private budgets as well as concern regarding natural resource use and protection.

New grasses have been developed over the past decade that may play a role in low-input-requiring sites. The warm-season turfgrasses, which are well adapted to Southern California, have been improved. To date, there has not been an evaluation of the performance of some of the newer grasses under reduced input cultural treatments. The objective of a study that was conducted at the UC South Coast Research and Extension Center in Irvine was to evaluate various aspects of quality of four turfgrass that were chosen for reduced-input practices, when irrigated with calculated optimum and less than optimum irrigation regimes and maintained with varying moderate to low level of nitrogen fertilization.

During the study, the seeded bermudagrass [Cynodon dactylon (L.)] was noted to performed abnormally and, on examination, a bermudagrass mite (Eriophyes cynodoniensis Sayed) infestation was identified so the species was removed from the study. Over the three year period, tall fescue (Festuca arundinacea Schreb.) decreased in turfgrass quality, color and density, especially for the lower input treatments. Buffalograss [Buchloe dactyloides (Nutt.)] and zoysiagrass (Zoysia Willd.) were shown to offer the best opportunity for performance with reduced irrigation input. Zoysiagrass quality and biomass production were the same at 100% and 70% of calculated evapotranspiration for warm-season turfgrasses while buffalograss retained cover and competitiveness at 40% of calculated evapotranspiration for warm-season turfgrasses. Buffalograss performance responded strongly to increased nitrogen fertilization while zoysiagrass was less influenced by increasing rates of nitrogen.