Water Conservation Potential and Quality of Non-turf Groundcovers versus Kentucky Bluegrass under Increasing Levels of Drought Stress

Abstract

Abstract In June 1991, a 2-year field study was initiated to examine if three non-turf groundcovers require less irrigation than Kentucky bluegrass (KBG). Irrigation treatments were based on decreasing percentage of évapotranspiration (ET) (100%, 75%, 50%, 25% and 0%). ET was estimated by the modified Penman equation using alfalfa as a reference crop. Plants receiving the 0% irrigation treatment were not irrigated and relied on precipitation for survival. The groundcovers studied were Kentucky bluegrass ‘Challenger’ ( Poa pratensis L.), creeping potentilla ( Potentilla tabernaemontani Asch.), goldmoss ( Sedum acre L.) and snow-in-summer ( Cerastium tomentosum L.). Data were collected on visual ratings, growth, soil moisture and canopy temperature. Optimum irrigation for KBG was 50% ET. Cerastium required irrigation at 50%-75% of estimated ET during the initial season (1991) for optimum appearance and growth. During 1992, the plants were better established and 25% ET was optimum. Potentilla required irrigation at the 75% ET rate for optimum visual quality. Sedum maintained a good aesthetic appearance at irrigation rates as low as 25% ET and could be considered as a water-conserving alternative to KBG