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The soil water and nitrogen (N) levels are the important factors affecting turfgrass growth. However, the impact of the water-N interaction on tall fescue (Festuca arundinacea Schreb) in terms of the N metabolism and plant morphology remains uncertain. Therefore, the objective of this study was to investigate the impacts of different N and water levels on the physiological and morphological responses of tall fescue. The experiment was designed with N (N-0, N-2, and N-4 representing N application rates of 0, 2, and 4 g m(-2), respectively) and irrigation [W-1, W-2, W-3, W-4, and W-5 representing field water capacities (FWCs) of 90 similar to 100%, 75 similar to 85%, 60 similar to 70%, 45 similar to 55%, and 30 similar to 40%, respectively] treatments, and the relevant indexes of the soil water content and soil NH4+-N and NO3--N levels as well as the physiology and morphology of the tall fescue were determined. The results demonstrated significant changes in the contents of soil water (SWC) and N and the physiological and morphological indexes, except for the enzymes related to N metabolism, including nitrite reductase (NiR), glutamate dehydrogenase (GDH), and glutamate synthetase (GOGAT). The water stress significantly enhanced the water and N use efficiencies (WUE and NUE), except the NUE in the W-5 treatment. The N stress significantly influenced the SWC, soil NO3--N content, and physiological and morphological indexes, excluding malondialdehyde, NiR, GOGAT, and above- (AGB) and below-ground biomass, resulting in the increased WUE and NUE. The application of a low N rate effectively alleviated the detrimental impacts of water stress on the SWC and glutamine synthetase activity. In conclusion, W-2 and N-2 are deemed more appropriate treatments for the low-maintenance measures of tall fescue turf. Among all the treatments, N2W2 is recommended as the optimal water-N interaction treatment due to its ability to conserve resources while still ensuring high turf quality.

来源平台：AGRICULTURE-BASEL