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ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Water Management and Conservation Research » Research » Research Project #445800

Research Project: Developing Sustainable Turfgrass Systems in the U.S. Southwest

Location: Water Management and Conservation Research

Project Number: 2020-21500-001-000-D
Project Type: In-House Appropriated

Start Date: Feb 22, 2024
End Date: Feb 21, 2029

Turfgrass is an important element of many urban and rural landscapes with positive impacts on the physical environment, economy, and quality of life for millions. However, the prevalence of drought, heat, and soil salinity in the desert U.S. Southwest are limiting factors for wide-spread utilization of turfgrasses. Therefore, the objectives of this project are: Obj. 1: Develop drought and heat tolerant turfgrass germplasm for use in hot and arid climates. 1A: Assemble and characterize different turfgrass species germplasm. 1B: Generate additional genetic variability through intra- and inter-specific hybridization of turfgrass species and characterize for resilience to environmental stresses. 1C: Employ high throughput phenotyping using proximal sensing as a quantifiable measure of turfgrass quality and stress tolerance. 1D: Determine genetic mechanisms and metabolites underlying environmental stress tolerance and enhanced turf quality. Obj. 2: Expand opportunities for environmentally sustainable utilization of turfgrass in arid environments. 2A: Evaluate the impact of management practices on greenhouse gas fluxes, carbon dynamics, and transpiration cooling for warm-season grasses in the desert. 2B: Define the effect of different management practices, water chemistry, and environmental conditions on water use on warm season turfgrasses. 2C: Investigate factors contributing to reduced turfgrass quality and restoration solutions within complex turfgrass systems.

1. Develop drought and heat tolerant turfgrass germplasm for use in hot and arid climates. 1A: Diverse germplasm of warm season turfgrass species will be assembled and evaluated in small plot in Maricopa, AZ to enhance for environmental stress tolerance and aesthetic value. Three levels of irrigation (80, 60 and 40% of estimated evapotranspiration (ET) replacement) will be examined. The field experiments will be complemented with studies in the controlled environments such as greenhouses or growth chambers. 1B: To generate additional variability and potential hybrids, hybridization will be conducted among different genotypes of bermudagrass and zoysiagrass. In bermudagrass, the tetraploids and hexaploids will be pollinated with the diploid to generate interspecific hybrids. Different species of zoysiagrass will be intercrossed. 1C: To enhances the identification of stress tolerant high quality turfgrass, a high throughput phenotyping (HTP) will be collected using ground-based and unmanned aerial vehicle equipped with proximal sensors. Plant performance for color, quality, and environmental stress tolerance will be assessed via a bi-weekly HTP and visual turfgrass assessment scale. 1D: Genomic analyses will focus on understanding and characterizing genetic mechanisms association with abiotic stress tolerance in turfgrasses using genome-wide association studies, transcriptomics, and metabolomics to identify genomic regions, candidate genes, gene expression networks, and metabolites underlying stress tolerance in turfgrasses. 2. Expand opportunities for environmentally sustainable utilization of turfgrass in arid environments. 2A: Turfgrass ecosystem services including carbon sequestration, effects on microclimate, and urban habitat will be assessed at different management scenarios in Maricopa and in urban Phoenix. Data on turf quality using a visual ranking and imaging, greenhouse gas flux (CO2, N2O, and CH4), soil volumetric water content, and electrical conductivity (EC) will be collected and analyzed. Carbon sequestration for different management scenarios will be quantified from seasonal soil samples. 2B: To educate the stakeholders on turfgrass water requirements, use of impaired water sources, management considerations under reduced irrigation, and management under shade will be conducted in greenhouse utilizing lysimeters. Separately, growth, quality, and water use will be characterized under different water quality irrigation, mowing heights, fertility regimes, and shade. ET will be determined gravimetrically by calculating the mean mass change of the 100% ETa lysimeters every 2-3 days. 2C: Study on heterogeneity and identify factors contributing to reduced turfgrass quality of complex turfgrass systems including irrigation coverage, photosynthetically active radiation variability, and soil characteristics will be conducted utilizing different water sources. Data on normalized difference vegetation index, irrigation audit, and multiple root and soil parameters impacting turfgrass performance and quality will be assessed.