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ARS Home » Plains Area » Temple, Texas » Grassland Soil and Water Research Laboratory » Research » Publications at this Location » Publication #367484

Research Project: Resilient Management Systems and Decision Support Tools to Optimize Agricultural Production and Watershed Responses from Field to National Scale

Location: Grassland Soil and Water Research Laboratory

Title: Field and simulation-based assessment of vetivergrass bioenergy feedstock production potential in Texas

Author
item MEKI, MANYOWA - Texas Agrilife Research
item Kiniry, James
item WORQLUL, ABEYOU - Texas Agrilife Research
item KIM, SUMIN - Oak Ridge Institute For Science And Education (ORISE)
item Williams, Amber
item OSORIO, JAVIER - Texas Agrilife Research
item REILLEY, JOHN - Natural Resources Conservation Service (NRCS, USDA)

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/19/2020
Publication Date: 5/20/2020
Citation: Meki, M.N., Kiniry, J.R., Worqlul, A., Kim, S., Williams, A.S., Osorio, J.M., Reilley, J. 2020. Field and simulation-based assessment of vetivergrass bioenergy feedstock production potential in Texas. Agronomy Journal. 112(4):2692-2707. https://doi.org/10.1002/agj2.20226.
DOI: https://doi.org/10.1002/agj2.20226

Interpretive Summary: Vetivergrass is a multi-purpose crop with untapped potential for biofuel production. We conducted a field study at Temple, Texas (TX) to determine and evaluate plant growth characteristics that make vetivergrass an ideal candidate bioenergy feedstock crop. The high biomass yield is due to the high leaf area index, amount of biomass produced per unit intercepted light (radiation use efficiency), and high growth rates. Plant tissue N and P concentrations varied over the growing season. Biomass yield was highly correlated to plant height and leaf area index. Data from the field experiment provided plant coefficients that were used to simulate vetivergrass biomass yield, its inter-annual variability, and spatially distributed production potential under rainfed and irrigated conditions across TX. Simulations were made over a 21- year time series for combinations of soils and climates across 21 agroclimatic zones. Simulated average dryland and irrigated biomass yields ranged from 2 to 20 Mg ha-1 and 6 to 27 Mg ha-1, respectively. There was high inter-annual yield variation for both dryland and irrigated conditions. These state-wide simulation model assessments complement field studies in a cost-effective way and will further allow bioenergy companies and investors to better estimate biofuel production potential for new crops such as vetivergrass.

Technical Abstract: Vetivergrass [Chrysopogon zizanioides (L.) Roberty] is a multi-purpose crop that has an untapped potential for biofuel production. We conducted a field study at Temple, Texas (TX) to determine and evaluate plant growth characteristics that make vetivergrass an ideal candidate bioenergy feedstock crop. Overall, the high biomass yield (avg.18.4±0.7 Mg ha–1) can be attributed to the high leaf area index (LAI, avg. 12.7±2.5), radiation use efficiency (RUE, avg. 2.2±0.1 g MJ–1), and crop growth rates that ranged from 2.7±0.1 to 15.7±0.1 g m-2 d-1 from early to late in the growing season, while plant tissue N and P concentrations ranged from 0.59% to 1.66% and 0.06% to 0.15%, respectively. Biomass yield was highly correlated to plant height (avg. 2.1±0.1 m) and LAI (Pearson, r = 0.96 and 0.77, respectively). Data from the field experiment provided plant coefficients that were used to develop an APEX (Agricultural Policy/Environmental eXtender) vetivergrass model to assess vetivergrass biomass yield, its inter-annual variability, and spatially distributed production potential under rainfed and irrigated conditions across TX. Simulations were made over a 21- year time series for combinations of soils and climates across 21 agroclimatic zones (ACZs). APEX simulated average dryland and irrigated biomass yields ranged from 1.9 to 20.2 (Avg., 10.2) Mg ha-1 and 6.3 to 27.4 (Avg., 17.2) Mg ha-1, respectively. There was high inter-annual yield variation for both dryland and irrigated conditions with CV percent values of 60% and 40%, respectively. These state-wide simulation model assessments complement field studies in a cost-effective way and will further allow bioenergy companies and investors to better estimate biofuel production potential for new crops such as vetivergrass.