100041 Effects of Precipitation Changes on Switchgrass Photosynthesis, Growth, and Biomass: A Mesocosm Study.

Poster Number 152-1007

See more from this Division: ASA Section: Agronomic Production Systems
See more from this Session: Bioenergy Systems Poster Competition

Monday, November 7, 2016
Phoenix Convention Center North, Exhibit Hall CDE

Chih-Li Yu1, Dafeng Hui1, Qi Deng1, E Kudjo Dzantor2, Suping Zhou2, Samuel Dennis3, Roger Sauve2, Philip Fay4, Weijun Shen5, Yiqi Luo6 and Terrance Johnson1, (1)Department of Biological Sciences, Tennessee State University, Nashville, TN
(2)Department of Agricultural and Environmental Sciences, Tennessee State University, Nashville, TN
(3)Agricultural & Environmental Sciences, Tennessee State University, Nashville, TN
(4)USDA, Temple, TX
(5)South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
(6)Microbiology and Plant Biology, University of Oklahoma, Norman, OK
Abstract:
Climate changes, including chronic changes in precipitation amounts, will influence plant physiology and growth. However, such precipitation effects on switchgrass, a major bioenergy crop, have not been well investigated. We conducted a two-year precipitation simulation experiment using large pots (95 L) in an environmentally controlled greenhouse in Nashville, TN. Five precipitation treatments (ambient precipitation, and -50%, -33%, +33%, and +50% of ambient) were applied in a randomized complete block design with "Alamo" switchgrass plants one year after established from tillers. The growing season progression of leaf physiology, tiller number, and height and aboveground biomass were determined each growing season. Precipitation treatment significantly affected leaf physiology, growth, and aboveground biomass. The photosynthetic rate in the +50% treatment was 18.7 µmol CO2 m-2s-1, significantly higher than other treatments. The biomass in the +50 % treatment was twice that in the -50% treatment. Compared to the ambient treatment, the -33% treatment did not influence leaf physiology, plant growth, and aboveground biomass, but the -50% treatment significantly reduced plant height and aboveground biomass. This study demonstrated that while switchgrass is a drought tolerant grass, severe drought significantly reduces its growth and biomass, and that high precipitation stimulates photosynthesis and growth.

See more from this Division: ASA Section: Agronomic Production Systems
See more from this Session: Bioenergy Systems Poster Competition