Researchers Say Perennial Biofuel Crops Could Use Same Water as Corn in Humid Climates

In Michigan, converting large areas of marginal farm land to perennial biofuel crops carries some unknowns, including how it could affect the balance of water between rainfall, evaporation and movement of soil water to groundwater.

A recent study from the Great Lakes Bioenergy Research Center and published in Environmental Research Letters looks at how efficiently "second generation" biofuel crops use rainwater and how these crops affect overall water balance. The study was led by Michigan State University professor and GLBRC scientist Stephen Hamilton.

Researchers used soil-water sensors to measure the rate of evapotranspiration occurring within each cropping system. Results show that the perennial biofuel crop system's evapotranspiration did not differ greatly from that of corn under both normal and drought conditions. This indicates that rain-fed perennial biomass crops have little impact on landscape water balances, whether on arable lands or on marginal lands.

Results also suggest that crop ET rates, and thus groundwater recharge, streamflow, and lake levels, may be less sensitive to climate change than has been assumed.