Water use overlooked in energy crop impact work
Water use has been ignored when the environmental impacts of bioenergy crops have been researched, according to new research.
The work, published in the Proceedings of the National Academy of Sciences Early Edition this week, claims efficient large-scale biofuel production by using large grasses like miscanthus or switchgrass rather than corn is 'exciting'.
But, the impact on water resources has been largely 'overlooked' by previous studies, according to researchers from the University of Illinois in the US.
According to the research miscanthus and switchgrass offer better yields for biomass per acre when compared to corn.
However, they both intercept light and rain differently from corn and lose more water through transpiration, which causes them to pull more water from the soil.
As a result large-scale adoption would see a reduction in soil moisture and runoff, but an increase in atmospheric humidity.
The university's professor of civil and environmental engineering, Praveen Kumar, said: "While we are looking for solutions for energy through bioenergy crops, dependence on water gets ignored, and water can be a significant limiting factor.
"There are many countries around the world looking into biofuel energy, but if they are adopting large grasses into their regular policy, then they need to take into account the considerations for the associated demand for water."
The work details the effects to the hydrologic cycle of large-scale land conversion, both now and as growing conditions change in the future.