Climate Change & Agriculture
Agriculture in an Era of Climate Change
Montana agriculture may not be greatly affected as global temperatures continue to rise-at least over the short term. Some climatologists suggest that certain sectors may even improve as growing seasons lengthen-expanded corn production, for example. Furthermore, to bolster production of new fuels, markets may move toward oilseed production or even cellulosic ethanol crops such as switchgrass and waste fibers from crops. Precipitation remains a concern, however. And weather data over recent years indicates that spring runoff occurs earlier than usual, which makes perennial water distribution issues an even more pressing problem. Should Montana become measurably drier, dry land yields would fall for all crops and average livestock forage production would also decline. Crop insurance availability and weather related damage claims are also areas of concern.
Several emerging trends in Montana agriculture are noteworthy in the context of climate change. The first is a general movement toward more “sustainable” agricultural practices, particularly certified organic production of food crops, beef, and other products. While seemingly tangential to the issues surrounding climate change, organic and sustainable management practices play a central role in addressing imbalances in carbon cycles.
Sustainable agriculture is a resource-conserving, integrated management strategy designed not to maximize production, but rather to maintain productivity indefinitely. The term is defined and used in congressional Farm Bill language dating back to 1990: Sustainable agriculture “enhances environmental quality and the natural resource base upon which the agricultural economy depends.” Additionally, sustainable agriculture makes “the most efficient use of nonrenewable resources” and integrates “natural biological cycles and controls.”
Since many conventional agricultural producers consider their management practices broadly sustainable, interest groups and lawmakers recently moved to standardize and certify producers who could meet highly-stringent “organic” production criteria. These standards prohibit use of inorganic fertilizers, pesticides and herbicides, growth hormones, and other specified synthetic agriculture inputs. In 2002, the USDA adopted national organic standards that spell out exactly what producers can (and cannot) do to become certified “organic.” Producers who meet independently monitored standards for land and management can market their agricultural products as “USDA Certified Organic.”
The transition of acreage in Montana to certified organic status is measurable and impressive. In 2008, 132,029 acres of cropland were certified organic with another 83,219 acres of pasture lands under certification. Montana is among the top four states in both categories. The conversion of acreage in Montana from conventional to organic status is occurring at about three times the rate of other states in the region. As recently as 2005, Montana led the country in the production of organic wheat, producing more than 5 million bushels on 56,000 acres of certified ground. While that production has flattened somewhat in more recent years, the projected conversion of acreage is expected to remain high. A major factor driving the conversion to organic is the high cost of fuels and petroleum-derived fertilizers. Organic farms are known to use significantly less fossil fuel and other petroleum-related inputs than is used on comparable sized farms.
Sustainable and organic forms of agriculture are broadly outlined here because their applications in Montana are known to significantly increase soil carbon when compared to conventional cultivation. A hallmark of sustainable and organic cultivation strategies is the use of “green manure” – the planting of soil-building cover crops during the fallow period. Less bare soil is exposed and more carbon conserved.
Conservation tillage and no-till practices are important agricultural strategies in Montana and elsewhere. These approaches essentially better preserve the topsoil structure and conserve soil carbon. Crops are planted into a previous year’s crop residue with minimal or no tillage. The soil may be sliced or drilled into for seed placement. The Montana Climate Change Advisory Committee identified about 5 million acres in Montana that is currently under some form of conservation tillage. The committee identifies approximately 9.5 million acres in Montana that could be converted to carbon-storing conservation practices.
Sustainable practices are also exercised on pasture and ranges in Montana. Studies have shown that more intensely managed pasture and range supports a more diverse species mix and maintain high soil carbon levels. Programs such as the federal CRP and other practices that set aside lands from production also serve to store soil carbon and are encouraged by the Montana Climate Change Advisory Committee.
Another emerging trend in Montana agriculture is carbon trading, whereby property owners can trade carbon credits on the Chicago Climate Exchange (CCX). The CCX is a global marketplace that offers voluntary legally binding emissions reductions with emissions trading and offsets for all six greenhouse gases. The carbon exchange rates fluctuate on the CCX, given market conditions.
The Montana Natural Resources Conservation Service (NRCS) offers a link to a carbon dioxide (CO2) evaluation tool for landowners. This tool is a voluntary mechanism to report soil carbon sequestration or emissions for any variety of land types. The exercise can prove useful to landowners wishing to take part in the emerging carbon trading markets.
One method to store or sequester carbon is in soil humus and in vegetation. The CarbOn Management Evaluation Tool - Voluntary Reporting (COMET-VR) is an online management tool that provides a simple and reliable method to estimate changes in soil carbon sequestration, fuel, and fertilizer use resulting from changes in land management. COMET-VR calculates in real time the annual carbon flux using a model simulation. Users of COMET-VR specify a history of agricultural management practices on one or more parcels of land. The results are presented as ten-year averages of soil carbon sequestration or emissions with associated statistical uncertainty values. Estimates can be used to construct a soil carbon inventory for the certain federal programs. For more information about the COMET-VR and about the tool visit the COMET-VR website.
For a review of current agriculture policies on agricultural carbon sequestration, go to Soil Carbon Sequestration in Agriculture: The U.S. Policy Context, MSU Ag/Extension Communications