Energy and Animal Agriculture

Most meat, eggs and dairy products are now produced on factory farms, huge industrial livestock operations that raise thousands of animals in confined conditions without access to pasture. Since the animals are unable to graze, factory farms require tremendous quantities of feed produced by industrial crop farms using the energy-intensive processes described above. About half of the 90 million acres of land used to grow corn ends up as feed grain. And corn makes up about 95 percent of feed grain production. Out of all acres of harvested cropland in the US, corn represents about 28 percent. Factory farms are also potential sources of ground and surface water pollution, which may require municipalities and treatment facilities to expend additional energy and resources on water treatment.

Some factory farms use methane digesters to generate energy. These digesters capture methane released during the decomposition of the huge quantities of manure generated onsite, and then burn the gas to produce electricity. Although this reduces emissions of methane (a potent greenhouse gas), the technology: doesn’t eliminate solid waste; fails to address other environmental, human health, social and animal welfare problems created by factory farms and typically requires large subsidies to remain economically viable. Despite being touted as a “green” energy source, methane digesters ultimately serve to subsidize and further entrench the environmentally and socially destructive model of industrial livestock production.

Impact of Energy Policy

Energy policy also affects agriculture. For instance, congressional mandates now require the production of billions of gallons of ethanol, which is primarily derived from corn. The US Environmental Protection Agency continues to hold corn derived ethanol rates high while allowing cellulosic ethanol production — which derives ethanol from grasses, wood or algae instead of crops — to stay at a low level. Corn grown for ethanol takes land away from food production and, in states where corn is irrigated, uses a significant amount of water.

Energy Efficiency and Sustainable Agriculture

The modern food system depends on energy not only to produce food and to process it, but also to transport it from farms to markets. Food grown in conventional sustainable systems both depend on fossil fuels but to vastly different extents. Conventional distribution networks and food hubs can be optimized to deliver food in an efficient manner, but gains in energy efficiency may be offset by other sustainability concerns. So while conventional agriculture may appear to be more energy efficient due to economies of scale, externalities like fertilizer pollution, greenhouse gas emissions and animal welfare concerns are not included in that calculation. On the other hand, sustainable agriculture principles may not always be the most energy efficient in absolute terms, but they produce numerous other benefits such as increased soil health, pest control, erosion reduction and carbon storage.

Ultimately, energy intensity/efficiency is just one aspect of agriculture. Weeding and pest management, for example, may be more labor intensive in more sustainable practices, but could reduce the need for herbicides and insecticides. While sustainable agricultural practices require energy inputs just as conventional systems do, many opportunities for efficiency exist, and the benefits that accrue to other elements of the food system should not be overlooked.