Iowa and Midwest agriculture has started to change in recent years. One visible change is the interest to grow crops for biofuel and bioproducts (referred to as “energy crops”). Fossil fuel usage contributes to the growing problem with greenhouse gases. Alternative energy options from plant material are more sustainable and environmentally friendly compared to our continued dependence on fossil fuels.
Iowa State University is highly dedicated to bioenergy crops and has established a bioenergy research farm just southwest of Ames (County Road R38, Figure 1),
coined as the Sustainable Advanced Bioeconomy Research (SABR) Farm. SABR is funded by the Center for Advanced Bioenergy and Bioproducts Innovation (CABBI) out of the University of Illinois. Corn and soybeans were planted to compare with the energy crops, miscanthus and biomass sorghum. Biomass sorghum is similar to grain sorghum and corn, is an annual C4 grass, but is photoperiod sensitive resulting in large plants and reduced grain production (Figure 2).
Multiple variables are measured and monitored on these plots starting this season and will continue for the duration of the study. First, leaf area index (LAI) is taken on a weekly basis to determine the ratio of leaf area above a square meter of ground area. LAI measurements are taken non-destructive and gauge plant development. Undergrads in the Heaton Lab have been trained to use the LI-COR LI2200C to measure LAI based on light interception by the canopy (how much light is above the canopy vs. below it) (Figure 3).
Additionally, the four large plots each contain an eddy flux tower, which contain a suite of LI-COR instruments (Figure 4). Eddy flux towers measure several above and below ground variables, including solar radiation, wind speed, precipitation, CO2 and water vapor fluxes (between land and air), and soil heat flux. Measurements from these towers are important to assess how the land and atmosphere “speak” with one another through the exchange of mass and energy
Finally, the main plots have artificial drainage systems installed, which will allow us to measure the amount of water that it leaving the plot as well as the quality of that water. Fifteen smaller plots will be established and will be tile drained in the 2020 growing season (Figure 1, in green), which will allow assessment of water quality and quantity under different nutrient application rates. This can provide insight into which management practices strike a balance between profitable yield and environmental quality.