Energy Efficiency Obtained by Growing Grain for Food

Ilya Gelfand, an MSU postdoctoral researcher and lead author of the study declared: "It's 36 percent more efficient to grow grain for food than for fuel." Ilya continued: "The ideal is to grow corn for food, then leave half the leftover stalks and leaves on the field for soil conservation and produce cellulosic ethanol with the other half."

There were some previous studies that looked at energy efficiencies for crops over shorter time periods, but none of them considered energy balances of an entire cropping system over many years like this MSU study did. The results can be seen in the April 19 online issue of the journal Environmental Science & Technology.

University Distinguished Professor of crop and soil sciences and one of the paper's authors, Phil Robertson, stated: "It comes down to what's the most efficient use of the land." He added: "Given finite land resources, will it be more efficient to use productive farmland for food or fuel? One compromise would be to use productive farmland for both -- to use the grain for food and the other parts of the plant for fuel where possible. Another would be to reserve productive farmland for food and to grow biofuel grasses -- cellulosic biomass -- on less productive land."

He, Gelfand and another co-author and an MSU associate professor of crop and soil sciences, Sieglinde Snapp, studied data collected from 1989 to 2007 at the W.K. Kellogg Long Term Ecological Research site. In order to provide a better understanding of natural and managed systems at the same time, that National Science Foundation-funded project studies ecology and environmental biology.

The scientists used four systems in order to compare the energy inputs and outputs of producing corn, soybeans and wheat grown: conventional tillage, no-till, low chemical input and organic, and then using all harvested plant material for either food or biofuel production. Energy balances for growing alfalfa, an important forage plant that can be used either for biofuel or for beef cattle feed were also studied by the scientists.

The ersults of the analysis revealed that using no-till production to grow grain for food is the most energy-efficient system for food or fuel production. Tractor fuel use during production is reduced by avoiding plowing with no-till management.

The study revealed that by producing a kilogram of corn for human food they were able to obtain more energy than converting the corn to either ethanol by processing or to meat by feeding it to animals. Another thing that the study also revealed was the fact that growing alfalfa for biofuel seems to be 60 percent more efficient than using it as cattle feed.

Roberstono further added: "This research is aimed at policymakers who have to decide how and where biofuels should be grown and the best way to encourage farmers to follow those suggestions."