Climate change is a looming, often depressing topic, which many people like to avoid. However, avoiding problems rarely produce any sort of solution. When tackling the issue of climate change, there are many approaches one can take. However, to solve a problem, you have to aim at the heart of conflict. In this case, fossil fuels.
Finding and using alternative energy sources instead of fossil fuels is critical for a sustainable future. Mackenzie Rathgeber, an undergraduate student of Dalhousie University in the Faculty of Agriculture, and Department of Plant, Food, and Environmental Sciences, is trying to do, just that.
The production of biomass for use as biofuel is not a new concept, however it is still important to move away from fossil fuels. Biofuels are plant-based energy sources from transforming plant biomass into liquid or gaseous forms. While biofuel crops have been historically derived from high energy input crops such as maize or soybean, Mackenzie is looking at using more sustainable, low input crops for biofuel; specifically perennial grasses. As producing the traditional high energy input crops increases greenhouse gases released into the atmosphere instead of offsetting them.
Switchgrass (Panicum virgatum) is a warm-season perennial grass that has been increasingly produced and used for biofuel. However in Atlantic Canada, research investigating the potential of switchgrass to be grown as a biofuel crop is lacking.
Mackenzie conducted her research in affiliation with Agriculture and Agri-Food Canada. She gathered data from well-established experimental plots located at the Nappan Research Farm, in Nova Scotia. Her objective was to determine the suitability of producing switchgrass and local forage species (timothy, reed canary, and tall fescue) as biofuel crops in Atlantic Canada, in their fifth year of production.
The experimental design was a split-plot design consisting of 4 forage species (switchgrass, timothy, tall fescue, reed canary) in main plots and cultivars in 1.5 x 3 m sub-plots. For switch grass there were 11 cultivars and the other forages each had 3 cultivars. Each cultivar was replicated 3 times.
The plots were harvested in mid October with a walk behind “Jerry Mower” where a 1.1 x 2.4 m swath was cut in the middle of each subplot. Each swath was weighed and ~250 g of grass was taken from each sample for further analysis.
Dry matter was determined by weighing each subsample before and after drying in a oven at 60 °C for at least 72 h. Samples were ground in a Wiley Mill to pass a 1 mm screen. The biomass yield, energy content, and ash content were determined to evaluate suitability as a biofuel crop.
Switchgrass had by far the highest mean biomass yield compared to the local forage species with 7468 kg/h, making it the best choice of the four species. While, timothy was still a good choice despite the lowest biomass yield. It had the highest mean energy content of 4284 cal/g, and the lowest ash percentage of 2.30%.
The switchgrass cultivar 'Blackwell' had the highest biomass yield (9847 kg/ha) of the switchgrass cultivars and 'Nebraska' had the lowest (5298 kg/ha) (P<0.001). There was no significant difference for energy content and ash percentage between the switchgrass cultivars (P>0.05).
Selection for highest biomass yielding switchgrass cultivars will result in the best energy yield.
The top four cultivars recommend for biofuel would be 'Blackwell', 'Shawnee', 'CaveInRock', and 'Carthage'.
Although this study only utilized data from the fifth year of production at this location, the observations have led to the conclusion that the switchgrass cultivars studied have good potential to be a productive and enduring biofuel crop in Atlantic Canada. Additionally the local forage crops studied have excellent potential to be produced as a biofuel crops in Atlantic Canada, especially timothy with its low ash and high energy values.