Bioenergy Alley Cropping System: Establishment on Marginal Fallowland in the Missouri River Floodplain.

Lignocellulosic biofuels are more sustainable in the long term than corn or other food crops based biofuel production. Therefore, a sustainable cellulosic biofuel production system should target non-prime agricultural land or marginal lands. Alley cropping systems consisting of perennial woody and herbaceous species have been suggested as an alternative biofuel production systems in river floodplains due to several environmental and ecological benefits. In the Midwestern United States, there is a potential to produce up to 6 billion gallons of renewable biofuels each year according to some recent studies. Establishment of a large scale biomass alley cropping system in a river floodplain could be beneficial from several aspects. In this study, an abandoned marginal river bottomland along the Missouri river floodplain was selected for the trial. Five short-rotation poplar (SRP) double rows 60 m long and 18 m apart were established with four alleys in between. Three perennial grasses (Big bluestem - Andropogon gerardii, Indian grass -Sorghastrum nutans, switchgrass - Panicum virgatum) and a one-third mix of these grasses were planted in four alleys. Since utilization of light resources differ depending on the alley cropping configuration, alleys were established in four different orientations to compare resource (e.g. light) utilization. However, frequent and prolonged flooding negatively influenced the trial establishment. Establishment of trees were impacted in patches where ponding occurred. The native vegetation comprising mainly Reed Canary grass (Phalaris arundinacea) prevented the three grasses from establishing. Chemical control regimes were established to control the weeds and help establish the experimental crops.