Effect of bioenergy crops in soybean fields on abundance and diversity of pollinators

The implementation of the 2007 US Energy Independence and Security Act requires increased production of cellulosic biofuels. While annual crops such as corn and soybean are still the predominant crops used for starch-based production of bioenergy, perennial prairie grass’s (e.g. switchgrass and Miscanthus),  flowering forbs (e.g. Jathropa), and woody plants (e.g. Salix) are being investigated as alternatives for second-generation biofuels crops. Marginal habitats with perennial crops, in addition to providing feedstock for biofuel production, can also positively affect various groups of organisms and accompanied ecological services. Along with providing natural enemies with over-wintering sites, alternative host species and alternative energy sources, perennial biofuel crops might provide important nesting and foraging resources to pollinating insects, thus supporting higher abundance and diversity of pollinators and greater pollination service. Preliminary results from sampling conducted in 2013 show greater abundance of pollinators in prairie treatments and prairie patches within alley cropping in contrast to willow and control plots.  The sampling design in 2014 was modified to focus on pollinators, to give better insight to suggested differences in pollinator abundance between multiple biofuel cropping treatments. We used sunflowers as sentinel plants and cages to exclude or allow pollinator access to flowers to estimate the effect of pollination on seed yield. We hypothesize that soybean fields with prairie treatment will have higher abundance and diversity of pollinators and that pollination service will be enhanced near prairie plots. Results and implications for development of an agronomically-realistic platform for production of bioenergy crops will be discussed.