Higher real energy prices, combined with a desire to reduce U.S. dependence on foreign oil and a concern about rural energy security, may provide incentives for agriculture to move toward integrated farming systems that supply at least part of their own energy needs.
“Crops, crop and forest residues, and energy crops planted on idle or marginal cropland could serve as feedstocks for ethanol, biodiesel, and methane production,” John A. Miranowski, professor of economics at Iowa State University, said at the USDA's Agricultural Outlook Forum 2005 at Arlington, Va.
While the U.S. produced some 2 billion gallons of ethanol during 2002 and production is rapidly increasing as new plants come on line and existing plants are expanded, he said the U.S. “has been slow to integrate farm systems that consume energy based on farm-produced feedstocks.
“Smaller facilities, such as ethanol plants, lack the economies of scale that can be realized by commercial plants in the 100 million to 200 million-gallon annual capacity range.”
Methane gas and wind energy, where wind is consistent enough, “have more potential” for on-farm energy production and use, Miranowski said.
Wind energy potential
“Wind energy has significant potential,” and the technology is “rapidly expanding and becoming competitive” in production of electricity.
Wind generators with annual capacity of 1.5 megawatts are “becoming the norm,” he said, and indicators point to 5 megawatt capacity being feasible in the not too distant future.
Integration of such systems into a farm operation “will be more viable if producers can tie into the electric grid to obtain energy when they have deficiencies and sell energy when they have surpluses.”
Methane technology “offers promise as an integrated source of farm energy,” Miranowski said, especially for livestock operations faced with residual disposal problems. “In some cases, methane digestion may be the most cost-effective solution, while providing power to the farm operation.”
Advances in solar energy technology are providing important on-farm energy substitution opportunities, he said, including providing water to remote livestock, powering electric fencing not near another power source, and providing lighting in more isolated areas.
Energy use in production agriculture peaked in 1978, Miranowski said, and from that point began a decline that amounted to 30 percent by 2002. At the same time, agricultural output increased by 45 percent.
“Real energy price increases…provided incentives for farmers to become more energy-efficient, switching from gasoline engines to more fuel-efficient diesel engines, adopting reduced tillage practices, matching power to equipment, shifting to more efficient machinery, and adopting energy-saving methods for crop drying, irrigation, heating, and ventilation.”
Energy use drop
The combined effects of growing agricultural productivity and increasing efficiency of fuel and other inputs was that energy use per unit of agricultural output dropped by 7 percent from 1978 to 2002, he said.
“Revolutionary advances in biotechnology and information” have also had “dramatic impacts on agriculture — offering a wide range of new plants resistant to pests, diseases, and herbicides,” Miranowski said.
This resistance to pests and herbicides has reduced the need for application of those materials, resulting in savings of energy for their manufacture and for on-farm application.
Research is under way to improve nutrient utilization in plants, he noted. With plants fixing their own nitrogen in the soil, the need for commercial fertilizer use would be reduced, along with energy requirements for fertilizer manufacture and application.
“Global positioning systems (GPS), yield and soil monitors, and geographic information system (GIS) data for precision farming systems have potential to bring more efficient pest control and use of nutrients, ultimately saving on both direct and indirect energy needs in crop production.”
Use of computers in monitoring the health condition of hogs and meat animals has resulted in an “information revolution” that has taken production from an era of “attentive husbandry” to an era of “informed husbandry.”
Computers, Miranowski said, are now used in a preventive approach to animal health care and reduced overall energy demand.