Author
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Springer, Timothy |
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Submitted to: Biomass and Bioenergy
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/23/2011 Publication Date: 1/25/2012 Citation: Springer, T.L. 2012. Biomass yield from an urban landscape. Biomass and Bioenergy. 37:82-87. Interpretive Summary: Biomass yield from urban landscapes is an untapped resource and utilization of urban landscapes for biomass-for-energy production would free agricultural landscapes for food production. In 2007 and 2008 the biomass production was estimated from an urban landscape consisting of a common-type bermudagrass lawn with two fruitless mulberry trees and one Austrian pine tree for shade in Woodward, Oklahoma, and the potential biomass yield for the City of Woodward. Each year in April, the lawn was dethatched and fertilized. Mowing began in mid-to-late May and biomass yield was estimated. In addition, the yield of fallen leaves and tree limbs from pruning operations were added to the lawn yield estimates for total annual biomass production. These data suggest that during high precipitation years it was possible to harvest from 13.5-to-19.0 Mg of dry biomass per hectare from an urban landscape and 8.0-to-12.3 Mg of DM biomass per hectare are possible for years with normal precipitation and temperatures. It was estimated that the city of Woodward could generate about 3,750 Mg of biomass dry matter in a normal rainfall year and about 6,100 Mg in a high rainfall year. In the USA there is an estimated 164 million Mg of biomass material harvested from urban landscapes annually. This number is based on a biomass yield of 10 megagrams per hectare (which was the low average biomass DM yield estimated from this experiment). This number could be larger if debris from natural disasters, such as, ice storms, tornados, hurricanes, and floods were added. Lawn clippings, fallen leaves and tree limbs are all potential sources of biofuels and most cities already collect and transport these materials to disposal/recycling sites. However, if every urban landholder provided their green biomass for energy production; cities could alternatively collect and transport these biomass materials to a local biomass fueled energy conversion plant where they could be used to produce electricity or converted into transportation fuels. Technical Abstract: Utilizing biomass from urban landscapes could significantly contribute to the nation’s renewable energy needs. In 2007, an experiment was begun to evaluate the biomass production from a bermudagrass, Cynodon dactylon var. dactylon (L.) Pers., lawn in Woodward, Oklahoma and to estimate the potential biomass yield for the City of Woodward. Each year in April, the lawn was dethatched and fertilized. Mowing began in mid-to-late May and biomass dry matter (DM) yield was estimated by harvesting four 1 x 16 m areas. In addition, the DM yield of fallen leaves and tree limbs from pruning operations added to the lawn yield estimates for total annual biomass potential. These data suggest that during high precipitation years it was possible to harvest from 13.5-to-19.0 Mg of DM biomass per hectare from an urban landscape and 8.0-to-12.3 Mg of DM biomass per hectare are possible for years with normal precipitation and temperatures. It was estimated that the city of Woodward could generate about 3,750 Mg of biomass dry matter in a normal rainfall year and about 6,100 Mg in a high rainfall year if every homeowner collected their lawn thatch, lawn clippings, tree leaves, and tree prunings for bioenergy production. On the basis of a 10 Mg ha-1 DM yield, there is an estimated 164 million Mg of biomass DM material collected and/or recycled in the USA from urban areas annually. Biomass from urban landscapes is an untapped resource and further research is needed to fully understand the potential of this resource. |
