Location: Agroecosystems Management Research2010 Annual Report
1a. Objectives (from AD-416)
The objective of this project is to determine the optimal mixture of native prairie vegetation for the most efficient means of sustainable production of biomass for electrical generation while maintaining wildlife habitat and other prairie conservation benefits.
1b. Approach (from AD-416)
We propose to develp a native biomass fuel mixture that will produce large quantities of biomass over a variety of margnal soil types under variable annual weather conditions. This mixture would also be easily established, persist in mixed stands for the long term (10-30 years), be harvested efficiently by machine, be easily processed and used in stocker furnaces for elecrical generation. The"biofuels prairie mix" will contain 16 species from at least five plant functional groups (C4 and C3 grasses, sedges, legumes and forbs). The "biofuels mix" will be compared with three other mixes: a control consisting of a pure stand of switchgrass, a stand of five species of productive warm-season grasses, and a "prairie reconstruction mix" comprised of 32 species typically used in prairie plantings. Treatments will be imposed in randomized, replicated plots, large enough for harvest with farm equiment and to provide sufficient material for test burning by Cedar Falls Utilities. The experimental design will be stratified by soil type. Baseline soil carbon data will be collected from the plots prior to planting prairie vegetation in the spring of 2008. Species composition, aboveground- and root biomass will be quantified in 2009, 2010, 2011, and 2012. Soil cores will be taken in 2012, to assess soil carbon changes under the vegetation treatments. Wildlife monitoring will begin in 2008 and continue through 2012.
3. Progress Report
Biomass productivity and carbon sequestration potential are being compared with a switchgrass control, a prairie reconstruction seed mix, and one other seed mixture without added fertilizer or tillage. The experiment has been implemented at two research sites: an alluvial site located in the Cedar River Natural Resource Area (CRNRA) and an upland site located on the University of Northern Iowa (UNI) campus. Deep core samples and surface soil samples from two field sites were analyzed for total carbon and total nitrogen, using dry combustion analysis during winter of 2009/2010 and spring/early summer 2010. Monitoring activities for this project include quarterly conference calls with UNI collaborators, field site visits once or twice per year, and a yearly meeting for data sharing with stakeholders and graduate students.