My name is Michael Bomford. I work for the Community Research Service at Kentucky State University, an historically black land grant university in Frankfort, Kentucky's capitol city. My research focuses on developing sustainable organic agriculture systems suitable for adoption by small farmers. Check out some of the projects I'm working on here.

This summer my student, John Rodgers, conducted an energy farm experiment on organic land at the Kentucky State University Research and Demonstration farm.

Cultivated land on the Kentucky State University Research Farm (left),
includes 12 acres managed according to organic standards (right).
See a rollover image showing how the land is used.

We grew food and energy crops on either side of a solar-heated high tunnel used for year-round vegetable production without fossil fuel heat.

Our energy crops were sweet sorghum, sweet potato, corn, and Jerusalem artichoke. Each crop was grown in four plots, randomly assigned to locations throughout the energy garden.

John Rodgers manages plots of four potential energy crops:

1. Jerusalem artichoke (yellow flowers, foreground)
2. Sweet potato (vines, being cut)

3. Corn (dry stalks)

4. Sweet sorghum (tall canes, background)

We planted all of crops in early June, and harvested them in September and October. The corn harvest was easy: We picked ears off the stalks, then dried them and removed the kernals of corn.

The Jerusalem artichoke harvest was easy, too. A little effort with a spading fork brought up a tremendous mass of starchy nodules from each plant.

Jerusalem artichoke root mass.

Research Assistant Brian Geier holds a Jerusalem artichoke top in
one hand, and its root mass in the other.

The sweet potato harvest was more difficult. Hand harvest with a spading fork missed a lot of tubers. We recovered more tubers with a potato plow attachment for a walk-behind tractor.

A potato plow (left) can be pulled by a walk-behind tractor (left), but requires the user to bear down heavily. The tool recovered more sweet potatoes than a spading fork, with very little crop damage, but required a lot of physical effort. Co-Investigator Tony Silvernail operates the tractor in this picture.

A 2.5 minute video about our sweet sorghum harvest is here.

Our initial analysis suggests that an area dedicated to sweet potato produces more than five times as much carbohydrate as the same area dedicated to corn. Since carbohydrates are the feedstock for fermentation, we expect sweet potato to produce five times more ethanol per unit area, too. Sweet sorghum was the runner up among the crops we grew, producing almost three times as much carbohydrate as corn.

We're fermenting subsamples from our harvest now, to see whether carbohydrate production translates into as much ethanol as we think it will.

John Rodgers will present our initial findings at the Kentucky Academy of Science meeting in early November.

John's study this year is a preliminary to a four-year study, beginning next season, to examine the effect of farm scale on energy, labor, and land use efficiency of food and energy crop production.

We will grow sweet sorghum, corn, sweet potato, and soybean at three different scales:

The study will be conducted in cooperation with the Post Carbon Institute Energy Farms network.