Discipline: Ecology Environmental and Earth Sciences
Subcategory: Ecology
Jaquantey Bowens - Tennessee State University
Co-Author(s): Kenya Collins, Sadiye Aras, Chih-Li Yu, Qi Deng, and Dafeng Hui, Department of Biological Sciences, Tennessee State University, Nashville, TN
Climate change and energy crisis are two important issues we are facing today. Bioenergy crops such as switchgrass can be used as sustainable energy resource as well as mitigating climate change. However, the interaction between switchgrass productivity and climate change such as precipitation change has not been well investigated. We conducted two precipitation experiments in Nashville, Tennessee to investigate switchgrass physiology, roots, and biomass under different precipitation intensities. We hypothesized that drought treatments will significantly reduce plant root growth, photosynthesis, and biomass. The experiments used randomized complete block design with five precipitation levels including a control (ambient precipitation), +33%, +50% of ambient to simulate wet, and -33% and -50% of ambient to simulate drought treatments. Root images were taken monthly. Leaf physiology were measured bi-monthly, and above-ground biomass were harvested and measured twice a year. Preliminary results from the study showed that, in the growing season, the photosynthetic rates in the +33% and +50% treatments were about 19.5 µmol CO2 m-2 s-1, significantly higher than other three treatments. The lowest one was found in the -50% treatment (17.26 µmol CO2 m-2 s-1). The biomass in the +50% treatment was the highest and the lowest was observed in the -50% treatment. This study indicates that although switchgrass is a drought tolerant grass, high precipitation stimulates switchgrass photosynthesis and growth. More data will be collected to investigate the variations among years. These findings are valuable for farmers to prepare and improve bioenergy crop production in future climate, particularly for these small and minority farmers.
Funder Acknowledgement(s): This study was supported by: 1. USDA CBG program; 2. NSF HBCU-UP program; 3. NSF IUSE program.
Faculty Advisor: Dafeng Hui, dhui@tnstate.edu
Role: I participated in the field measurements and root image processing.