MP 2009-09

As the price of traditional fossil fuels escalates, there is increasing interest in using renewable resources, such as biomass, to meet our energy needs. Biomass resources are of particular interest to communities in interior Alaska, where they are abundant (Fresco, 2006). Biomass has the potential to partially replace heating oil, in addition to being a possible source for electric power generation (Crimp and Adamian, 2000; Nicholls and Crimp, 2002; Fresco, 2006). The communities of Tanana and Dot Lake have already installed small Garn boilers to provide space heating for homes and businesses (Alaska Energy Authority, 2009). A village-sized combined heat and power (CHP) demonstration project has been proposed in North Pole. In addition, several Fairbanks area organizations are interested in using biomass as a fuel source. For example, the Fairbanks North Star Borough is interested in using biomass to supplement coal in a proposed coal-to-liquids project, the Cold Climate Housing Research Center is planning to test a small biomass fired CHP unit, and the University of Alaska is planning an upgrade to its existing coal-fired power plant that could permit co-firing with biomass fuels. The challenge for all of these projects is in ensuring that biomass can be harvested on both an economically and ecologically sustainable basis

No-till Forage Establishment in Alaska

We assessed the effectiveness of no-till forage establishment at six Alaska locations: Anchor Point, Sterling, Point MacKenzie, Palmer, Delta Junction, and Fairbanks. Directly seeding grass into established grass stands generally did not improve forage yields or quality. Seeding rate had little effect on establishment of newly seeded forages in no-till. Grass yields were depressed when companion crop yields were high, and they typically did not recover in subsequent years. Red clover established well, producing high yields of good quality forage under no-till at Point MacKenzie, but established poorly at Anchor Point and Delta Junction. These results indicated that no-till seeding of most forage crops into declining grass stands is not likely to be successful in Alaska with current available technology

Harvest and Nitrogen Management of Three Perennial Grasses as Biomass Feedstock in Subarctic Alaska

High energy costs in high-latitude regions have generated interest in the feasibility of bioenergy cropping. The goal of this study was to determine the N response and best harvest regime for biomass production of three perennial, cool-season grass species—tufted hairgrass (Deschampsia caespitosa (L.) P. Beauv.), slender wheatgrass (Elymus trachy­caulus (Link) Gould ex Shinners), and smooth bromegrass (Bromus inermis Leyss)—at two locations in central Alaska. Maximum dry matter yields were 11.3 Mg ha-1 for smooth bromegrass, 8.1 Mg ha-1 for tufted hairgrass, and 8.0 Mg ha-1 for slender wheatgrass, but yields varied greatly among years. We found a linear N response in most cases, with highest yields at the 100 kg N ha-1 application rate. Yields for the double-harvest regime usually did not vary significantly from those of the fall harvest, but spring harvest sometimes reduced yields dramatically. Biomass in the spring harvest was usually dry enough not to require additional drying for storage. Results of this study indicate it may be possible to produce grass biomass yields high enough for use as bioenergy feedstocks in central Alaska, but questions remain about the best management practices and the economics of growing bioenergy crops in Alaska.Les coûts élevés de l’énergie en haute latitude incitent les gens à se pencher sur la faisabilité d’entreprendre des cultures bioénergétiques. L’objectif de cette étude consistait à déterminer la réponse à l’azote et le meilleur régime d’exploitation pour la bioproduction de trois espèces de graminées vivaces en saison fraîche, soit la deschampsie cespiteuse (Deschampsia caespitosa (L.) P. Beauv.), l’élyme à chaumes rudes (Elymus trachycaulus (Link) Gould ex Shinners) et le brome inerme (Bromus inermis Leyss), à deux endroits du centre de l’Alaska. Le rendement maximum de matière sèche était de 11,3 tm ha-1 dans le cas du brome inerme, de 8,1 tm ha-1 dans le cas de la deschampsie cespiteuse et de 8,0 tm ha-1 dans le cas de l’élyme à chaumes rudes, bien que les rendements aient connu d’importantes variations d’une année à l’autre. Nous avons trouvé une réponse linéaire à l’azote dans la plupart des cas, les rendements les plus élevés étant ceux de la dose d’application de 100 kg N ha-1. Le rendement du régime à double récolte ne variait généralement pas beaucoup du régime à récolte d’automne, bien que les récoltes du printemps donnaient parfois un rendement considérablement réduit. De manière générale, la biomasse de la récolte du printemps était suffisamment sèche pour ne pas avoir besoin d’être asséchée davantage avant d’être stockée. Les résultats de cette étude indiquent qu’il peut être possible de produire des rendements en biomasse suffisamment élevés à partir de graminées pour être utilisés comme charge bioénergétique dans le centre de l’Alaska, mais cela dit, il y a toujours lieu de répondre aux questions portant sur les pratiques de gestion exemplaires et le caractère économique des productions bioéner­gétiques en Alaska