Grant: Discovery Grants Program - Individual

Human-induced climate change maybe the greatest environmental challenge ever faced by humankind. Amongst the solutions to decrease greenhouse gas emissions is a greater reliance on biologically, environmentally, and economically effective biofuels. Although much emphasis in North America has been put on bioethanol derived from corn and wheat, without addressing the greenhouse gas emissions derived from the inputs required to produce these crops, the greenhouse gas savings will be marginal. The production and use of nitrogen (N) fertilizer is the single largest source of greenhouse gas production in the production of these crops. This is largely due to the fact that after its application in the field a proportion of N fertilizer is converted to nitrous oxide, a gas which is 300 times more powerful than carbon dioxide as a greenhouse gas. Sugarcane is the most efficient bioethanol crop in tropical climes because of high biomass yield, its efficiency at accessing and using soil N, and because the crop can be infected with bacteria which provide N to the plant in a process known as biological N fixation (BNF). BNF is the bacterial conversion of N from the atmosphere to ammonium, a form of N which can be used by plants. ) In temperate climes, sugar beet is the most common sugar crop for the production of bioethanol and is much more efficient as a bioethanol feedstock than many other crops. However, recommended rates of N fertilizer for sugar beet crops are commonly 100 kg N per ha. The biological, environmental and economic efficiency of sugar beet could be greatly increased if a portion of its N requirement could be offset by BNF in the plants. The long-term objective of my research program is to advance knowledge in beneficial plant-microbe interactions and to develop plant-microbe combinations which increase the efficiency and sustainability of cropping systems. The objective of my research over the next 5 year period will be to identify and characterize symbioses between nitrogen-fixing bacteria and sugar-rich crops, particularly sugar beet, but also sweet pearl millet and sweet sorghum.