North American prairie is a special natural resource.  The location of prairie on the planet makes it a mega food producer.  Our prairies get the right amount of precipitation, warm temperatures, and cold temperatures to create a unique ecosystem that can only occur in the central part of America and Canada.  And once discovered by settlers, prairie has, and is, providing food and fuel to the world.

FOOD

Rangelands

Rangelands are different from pasture lands in that rangelands grow primarily native vegetation, rather than plants established by humans. Rangelands are also managed principally with extensive practices such as managed livestock grazing and prescribed fire rather than more intensive agricultural practices of seeding, irrigation, and the use of fertilizers.

Vast grasslands remain and function as rangelands, a type of agriculture. Rangelands provide a balance between maintaining natural ecosystems while providing meat products for human consumption.Cattle thrive on the short, warm-season grasses such as buffalo grass and blue grama of short grass prairie, which are rich in protein.

European settlers brought agriculture and domestic livestock to the mixed grass and short grass prairie.   Due to a more rugged topography and less precipitation, this mixed grass and short grass prairie did not undergo the conversion to agriculture that occurred in tall grass prairie regions.   Thus great deal of the land remains in native grass, which is used as rangeland for cattle.

Crops

The principle crops of the mixed grass and short grass prairies are corn, soybeans and alfalfa.  Alfalfa is most often harvested as hay since has the highest feeding value of all common hay crops. Grain sorghum is also grown in these regions and is used as fodder for poultry and cattle.  Hard winter wheat, used to make flour, dry beans, and sunflowers are also products of the mixed grass and short grass prairies.

The deep, organic-rich soil built up by tall grass prairie is made for agriculture. Prairie grasses sink their roots deep underground.  The natural decomposition of these prairie plants, in particular their root systems, added layers of organic matter to the soils and helped create the rich, black soils in Iowa, Illinois, Minnesota, and Nebraska.  The corn-belt from Kansas to Oklahoma is probably the best agricultural land in the world.

BIOFUEL

Bioethanol is a form of renewable energy that can be produced from agricultural feedstocks. It can be made from very common crops such as soybean and corn.  These feedstocks are processed into ethanol.

Cellulosic ethanol is a biofuel produced from wood, grasses, or the non-edible parts of plants.   Unlike corn and soybeans, which are major food crops, prairie grasses are not used for human consumption. Prairie grasses can be grown in infertile soil, eliminating the cost of adding nutrients to the soil.  Switchgrass and Miscanthus, native prairie grasses, are two materials scientists are using to create cellulosic ethanol, due to their high productivity per acre. Switchgrass yields twice as much ethanol per acre as corn; however, corn is currently easier and less expensive to process into ethanol.

It used to be that we just put used coffee grounds in the compost heap or directly into the garden, but now it seems that used coffee grounds make a great feedstock for making biodiesel. I have just gotten used to the smell of french-fries emanating from the tail pipes of  some city buses and a few pickup trucks … the smell of coffee might be more than I can handle.

According to a study carried out at the University of Nevada Reno, coffee, the dregs of most used beverage in the world have value as an oil source for the production of high-quality biodiesel. In an article published in the March issue of Biodiesel Magazine, Susanne Retka Schillthe reports that the concept of using coffee to produce diesel fuel has been around for a few years anyway. It seems that bio-fuel pioneers down in Brazil have been using excess and reject coffee beans to make biodiesel for some time now. The new research indicates that used coffee grounds contain from 11 percent to 20 percent oil that results in a stable, but sulfur-rich biodiesel. In order to meet ASTM standards for on-road diesel fuel, the sulfur needs to be removed first.

the University of Nevada, Reno study concluded that if all the coffee grounds were collected from Starbuck’s they could be processed into about 2.9 million gallons of biodiesel each year. And once the oil is extracted from the coffee grounds, the remains can be turned into pellets and used as a heating fuel. The scientists working on the project realize that coffee grounds can really only amount to a small fraction of fuel needs globally, but I believe that their work is important because it makes clear that solutions to our fuel issues can be found in unlikely places, if only we can see them.

I know I would gladly run coffee biodiesel in my tractors and pickup, if I could find it. It makes more sense to me to take a waste product and turn it into biodiesel than it does to grow a crop like soybeans just for that purpose. What do you think?

Just when you think the only biofuel source will come from conventional farming with conventional crops, the scientists at the USDA’s ARS discover something new and interesting. This time the plant in question is a shrub called Guayule (pronounced why-YOU-lee) and it is native to the American Southwest. This desert shrub produces high quality latex that lacks the proteins associated with most latex allergies and the material that remains after extracting latex contains about the same amount of energy as a similar quantity of charcoal.

The medical industry is excited about guayule’s latex because it is of sufficient quality to produce premium gloves, tubing, sheets and other products that when produced from the rubber tree can cause deadly allergic reactions in some patients. What’s even cooler about this latex source is that it is extracted with water, which puts less strain on the environment than organic-solvent-dependent processes.

Once the latex is gone, the remaining sawdust-like plant material (called bagasse) could be burned directly, but it also shows excellent potential as a source of ethanol, bio-oil and synthetic gas.

Guayule is a perennial, so it need be planted only once for many years of harvest. According to ARS scientists, the plant requires no herbicide once it is established and isn’t susceptible to any significant insect, fungal or bacterial pests. The branches can be harvested as soon as two years after planting under ideal conditions. And guayule can be re-harvested every year and a half thereafter. Now that’s exciting.

I don’t think that guayule is any panacea, but it is an interesting desert shrub that’s easy and ecologically inexpensive to grow. Guayule could be part of a global solution in the long term.

Read more about guayule here.  

Photos courtesy ARS: Top photo by Jack Dykinga; bottom photo by Peggy Greb.