Effects of Kikuyugrass invasion on soil respiration rate and quality of cool season turf

Present study investigated the effect of Kikuyugrass invasion on soil respiration rate, turf quality and above-ground biomass of cool season turf which composed of Kentucky bluegrass, perennial ryegrass and tall fescue. Results showed that Kikuyugrass invasion reduced diurnal soil respiration rate, soil temperature and soil water content. Moreover, Kikuyugrass invasion also changed the soil respiration curve but showed no effect on maximal soil respiration rate (3.68 μmol·m-2·s-1). Soil respiration rate showed a significant positive correlation with soil temperature, but negatively correlated with soil water content in cool-season turf without Kikuyugrass invasion. However, no significant correlation between soil respiration rate and temperature was found after Kikuyugrass invasion. In addition, Kikuyugrass invasion significantly increased turf above-ground biomass (P＜0.05) but decreased total leaf chlorophyll content (P＜0.05). Kikuyugrass invasion led to poorer turf quality in terms of Nine Points System, e.g. color, texture, and surface uniformity were significantly decreased by Kikuyugrass invasion.