Date of Award

5-2009

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Plant and Environmental Science

Advisor

PARK, DARA M.

Committee Member

MCCARTY , LAMBERT B.

Committee Member

LIU , HAIBO

Committee Member

TOLER , JOE E.

Committee Member

STONE , KENNETH C.

Abstract

Population growth and recurring drought conditions have placed high demands on freshwater resources in South Carolina. Thus, turfgrass irrigation management practices that reduce freshwater use while maintaining quality turfgrass need to be identified.
Previous research in the arid Southwest USA documents water conservation on bermudagrass by using saline water sources and subsurface drip irrigation (SDI) systems. A field-scale facility was constructed in Florence, SC, to evaluate `Tifway' bermudagrass
(Cynodon dactylon (L.) Pers. X C. transvaalensis Burtt Davy) quality, growth, and rootzone characteristics when subjected to saline (3.15 dS m-1) or freshwater (0.07 dS m-1) irrigation, SDI lines spaced 41 or 81 cm, and irrigated to replace 65 or 100% ETp. For eight-week periods during the summer months of 2007 and 2008, weekly quality was monitored visually and by documenting the spectral reflectance of a near-infrared and a red wavelength. Growth was assessed by clipping yields, stolon counts, and root mass determinations. Soil electrical conductivity (ECe) was assessed for three soil depths at pre, mid, and post experiment each year. Turfgrass average quality scores were acceptable each year even though the 2007 experiment encompassed an extreme drought
period. Observed wilt during the 2007 experiment suggests that additional saline water, or cycling with freshwater may be necessary during extreme drought periods. Post experiment shoot density and root mass as well as mid and post experiment ECe were greater from saline irrigated bermudagrass than freshwater irrigated bermudagrass in 2007. There was minimal influence from factor treatments, and only for post-experiment measurements in 2008. These results suggest that saline water can be applied at reduced volumes through a SDI system during periods of high freshwater demand to maintain quality bermudagrass.
This experiment also evaluated the relationship between the qualitative (visual) and quantitative (spectral reflectance) assessment of quality and the relationship of spectral reflectance to primary stress factors (soil moisture and soil salinity). The two
forms of quality assessment were positively correlated for both experiments. Spectral reflectance was not as consistently correlated with soil moisture during the 2007 experiment as compared to 2008. However, spectral reflectance was positively correlated
with ECe during the 2007 experiment in which drought persisted, but not in the 2008 experiment. Monitoring spectral reflectance allows for assessment of turf response to primary stress variables.

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Horticulture Commons

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