Increasing nitrogen use efficiency and energy ratios of biofuel grasses with nitrogen fixing bacteria

在21世纪世纪，人类面临的两大挑战将是能源供应和气候变化。生物燃料是这两个挑战的结合点。从能量和经济角度来看，作物生产中最昂贵的投入之一是氮肥。减少氮肥的施用也将减少与氮肥施用有关的强效温室气体一氧化二氮的排放。可用于生产用于生物燃料生产的纤维素生物质的潜在作物是快速生长的草。这三个可能最适合加拿大的条件是芒草，柳枝稷和芦苇金丝雀。前两种可以在加拿大南部生产，后者可以在更北的地方生产。 在加拿大的条件下，所有三种都可以生产超过10吨公顷的可加工生物质。 减少氮肥需求的一种方法是依靠生活在作物根部附近、根部或根部中的根际细菌的生物固氮。 我们建议隔离自由生活的固氮根际细菌站芒草，柳枝稷和芦苇金丝雀草站已经生长了很少或没有氮肥至少15年。 将筛选分离菌株的固氮能力。 我们将测试这些菌株沿着几个众所周知的固氮根际细菌，芒草，柳枝稷和芦苇草在受控环境条件下，每种作物的最佳两个将被确定。 将对这些菌株进行表征，并通过16S rRNA序列数据确定其分类地位。 然后，最好的菌株将在田间条件下进行测试，首先在麦克唐纳校园农学研究站已经建立的柳枝稷上进行测试，然后在所有三种作物的两个季节中进行测试。 这些数据将用于确定作物生产力、氮素利用效率和能量比。 开发需要很少氮肥的生物燃料作物生产系统将改善生物燃料生产的经济性和能量学。 这将促进生物燃料能源部门的发展，将减少温室气体排放，并导致农村复兴。

Two of the greatest challenges to humanity during the 21st century will be energy supply and climate change. Biofuels are where these two challenges come together. One of the most expensive, both energetically and economically, inputs into crop production is nitrogen fertilizer. Reductions in nitrogen fertilizer applications will also reduce emissions of the potent greenhouse gas nitrous oxide, associated with N fertilizer applications. Among the potential crops utilizable for the production of cellulosic biomass for biofuel production are the fast growing grasses. The three for these probably most appropriate to Canadian conditions are Miscanthus, switchgrass and reed canarygrass. The first two can be produced in southern Canada and the latter further north. Under Canadian conditions all three can produce yields in excess of 10 t ha-1 of processable biomass. One way to reduce nitrogen fertilizer requirements is to rely on biological nitrogen fixation by rhizobacteria living near, on or in crop roots. We propose to isolate free-living nitrogen-fixing rhizobacteria from stands of Miscanthus, switchgrass and reed canarygrass stands that have been grown with little or no nitrogen fertilizer for at least 15 years. Isolated strains will be screened for ability to fix nitrogen. We will test these strains along several well known diazotrophic rhizobacteria, on Miscanthus, switchgrass and reed canarygrass under controlled environment conditions and the best two for each crop will be identified. These strains will be characterized and their taxonomic status determined through 16S rRNA sequence data. The best strains will then be tested under field conditions, first on stands of switch grass already established at the Macdonald Campus agronomy research station and then on purpose grown stands of all three crops for 2 seasons. The data will be used to determine crop productivity, nitrogen use efficiency and energy ratio. The development of biofuel crop production systems that require little nitrogen fertilizer will improve both the economics and energetics of biofuel production. This will facilitate the development of the biofuels energy sector, will reduce greenhouse gas emissions and lead to rural renewal.