Field and simulation‐based assessment of vetivergrass bioenergy feedstock production potential in Texas
- Agronomy journal 2020 v.112 no.4 pp. 2692-2707
- Chrysopogon zizanioides, agricultural policy, agronomy, arid lands, bioenergy, biomass production, complement, cost effectiveness, feedstocks, field experimentation, fuel production, irrigation, leaf area index, plant growth, plant height, plant tissues, radiation use efficiency, simulation models, time series analysis, Texas
- 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, TX, to determine 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) and crop growth rates that ranged from 2.7 ± 0.1 to 15.7 ± 0.1 g m⁻² d⁻¹. Plant tissue N and P concentrations ranged from 0.59–1.66% and 0.06–0.15%, respectively. Surprisingly, the radiation use efficiency (RUE, avg. 2.2 ± 0.1 g MJ⁻¹) was not high relative to other highly productive grasses. 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 Agricultural Land Management Alternatives with Numerical Assessment Criteria (ALMANAC) vetivergrass model to assess dryland and irrigated interannual and spatial biomass yields across Texas. ALMANAC simulated dryland and irrigated yields ranged from 0.8–39.3 (avg. 17.2) Mg ha⁻¹ and 9.1–47.0 (avg. 25.4) Mg ha⁻¹, respectively. There was huge spatial variation in dryland and irrigated yields, with CV values of 20 and 15%, respectively. Similarly, dryland and irrigated inter‐annual yields respectively had CV values of 25 and 17%. State‐wide simulation model assessments complement field studies, and furthermore allow bioenergy companies and investors to better estimate biofuel feedstock potential for new crops such as vetivergrass.