Bioenergy production potential on marginal land in Canada

Abstract

Biomass is an important source of renewable energy that has the potential to reduce greenhouse gas emissions. Some food crops, such as corn, can be used as feedstock for bioenergy production. Under limited cultivated land resources, this may lead to increased food prices due to resource competition between food and fuel. Some energy crops, such as switchgrass and hybrid poplar, can be grown on marginal lands which are not profitable for food crops due to low productivity. Thus, identifying and developing marginal land for bioenergy production could relieve the competition on land resources. The focus of this study was to assess the potential of Canadian marginal land for bioenergy production. The area of available marginal land was determined using a GIS overlay of a land suitability rating system (LSRS) and a land cover map of Canada. We assumed that bioenergy crops would essentially replace livestock production on rangelands (grassland and shrubland), but would not affect environmentally sensitive protected land. The production costs of growing energy crops on marginal land were then analyzed using a biomass production cost model. The results showed that about 9.48 million hectares could be identified as available marginal land in Canada. If this land is fully utilized for growing energy crops, the production of bio-fuel would be 33 million tons (under switchgrass) or 380 million tons (under hybrid poplar). The average Canadian production cost of switchgrass is about $318 ha−1, which is slightly lower than that for hybrid poplar ($340 ha−1 for Alberta, and $436 for Ontario). Although economics of plantation hybrid poplar looks positive, such is not the case for switchgrass or coppiced poplar. Growing hybrid poplar as a feedstock for bioenergy production on marginal land is an economically viable agricultural activity when the biomass price is greater than $18 per ton or with subsidies from government. Bioenergy production on marginal land in Canada could be helpful in securing food and energy supply, but would have a negative impact on the livestock industry.