Biofuels are energy sources derived from recently living organisms or their by-products, such as animal manure. As these organisms are constantly being produced, biofuels are renewable and not in limited supply unlike natural resources, such as petroleum and coal, which take millions of years to form. Yet there are problems associated with biofuels; all plants capture and use carbon dioxide from the air. In order to convert the plants into energy, they need to be burned, and burning them emits the CO2 back into the atmosphere. Including the further oil costs and CO2 emissions caused by the tractors needed to produce the crop and the trucks that transport it, many argue that traditional biofuel production just hasn’t been worth the effort.

But prairie grasses bury significant amounts of CO2 in the soil and in their deep roots, which causes a large portion of the CO2 to stay in the ground after they are burned. Tillman’s team calculated the total amounts of CO2 released during production – including that emitted through transportation, etc. and found the results to be “carbon negative” – meaning that prairie grasses capture more CO2 into the ground than the amount released into the atmosphere during their harvest.

Further, Tillman’s team discovered that the grasses produce 50% more energy than other sources of biofuel. Interestingly, the plots that included a variety of strains as opposed to a single strain produced more energy.

As of now, prairie grasses are far from being useable, as production is up to five times more expensive than traditional fossil fuels. But the fact that prairie grasses can grow on sandy and poor soil and do not require any irrigation, fertilizer, or pesticides will be the determining factor for the increase in market demand.