How Climate Change May Affect Agriculture

The title of this article gives you the hope that there is a chance that climate change might spare agriculture. However, as more research is being done, we are finding that this is not the case for us in the agricultural industry. Climate change has already begun to force us to adapt to shifting weather patterns. Our rains in the spring have been increasing in severity and length.  A large percentage of the corn-belt has been forced to plant later and harvest later. Fortunately for our late harvests, we are now seeing an increased two weeks to the average length in the growing season due to a rise in the total average temperature as well.  However, with an increased average temperature we are seeing new invasive species, more insect pests, and increased plant & animal pathogens. The other extreme to this pattern of late precipitation and rising temperature is in the form of drought, seen now in the south-western states.  Hotter temperatures mean we are seeing a quicker drying of the soil. This condition is leading to more forest fires. The forest fire season is now 60 days longer than it was 30 years ago.


The cause of these climate changes, as many of you already know, is from an excessive amount of carbon being released into the atmosphere in the form of carbon dioxide. Since recorded history, the average global temperature has risen 1.5 degrees Celsius. In 2012, we as a planet had 52 gigatones of CO2 emissions. Scientist feel that we at least need to lower that number to 41 gigatones if we are going to have a chance to limit global warming to no more than 1.5 degrees Celsius. Scientists believe that if temperatures continue to increase beyond 2 degrees C, we may reach a tipping point in world climate change from which there is no return.

Plants use up CO2 from the atmosphere and store it in the form of carbon in the soil through the process of photosynthesis. Until recently, this has been the method in which the earth has maintained balance and prevented excess carbon dioxide from escaping into the atmosphere. Now though, CO2 is escaping at a rapid rate leading to climate change, and agriculture has been one of the main contributors to this. Slash-n-burn of forested areas and high-tillage agriculture both are the main catalysts in increasing microbial activities which release carbon from the soil.

Addressing the threats of climate change, Tom Vilsack the National Agricultural Secretary, has established a Midwest Climate Hub at the USDA Agricultural Research Service National Lab in Ames, Iowa.  The Climate Hub will deliver science-based knowledge with practical information and program support to farmers, landowners, and resource managers to strengthen agriculture under increasing climate variables. The Midwest Hub will translate climate change projections into potential impacts on agriculture and forestry. The Hub provides an assessment of the risks to agriculture and forestry to help land managers better understand the potential impacts of a changing climate. The Midwest Hub is using the U of I Extension and USDA Service Agencies, as well as public/private partnerships like Illinois Stewardship Alliance in its outreach of information. This spring I attended a webinar held at the U of I Extension offices which were held in different regions of Illinois. Jerry Hatfield from the Midwest Hub in Iowa talked about the risk facing farmers in the near future from the potential excess temperatures during day-time and continuing into the night-time. This 24 hour period with no recovery time will have negative effects on yields during a critical time of pollination in corn and soybeans. Look to see more programs in the near future from the Midwest Climate Change Hub.

So, what can you do now to prevent some of these effects? Following a simple shift in how we farm could provide a sort of “sink” to capture 100% of the carbon currently being lost.  A carbon sink is something that captures and stores more carbon dioxide than it releases back into the atmosphere. Before we burned them for energy, fossil fuels were good carbon sinks because they were stored deep below the surface and the carbon there was not able to be released. The carbon that is stored from photosynthesis in our topsoil is a more vulnerable carbon sink. Poor topsoil management, which increases the number of microbial organisms that change carbon into carbon dioxide,  is now accountable for 1/3 of today’s greenhouse gas emissions.

As a farmer who is extremely concerned about the risk of climate change extremes, I want to see agriculture as the solution. First and foremost we need to eliminate the excessive length of time our soils sits bare before and after our cash crops. Bare soils are detrimental to carbon sequestration and overall soil health. Conservation tillage is the first step in improving your soils health. The less you disturb the soil the less the microbes are stimulated to turn carbon into carbon dioxide. Leaving the residue on the surface and not tilling it into the soil is the beginning step to good soil health.  Building up your soils organic matter plays an important role in this soil health process.  The more organic matter in the soil, the greater the water holding capacity, and the more efficient the nutrient uptake.  Once you have no-till practices in place adding a cover crop mix is the second step to jump starting the soil health process. Cover crops add a long list of benefits with carbon sequestration and improved soil health being just two of them.  The third step is adding more permanent crops like alfalfa to your crop rotation. Adding a perennial crop will ensure that the land is not being left bare and soil carbon will be fixed and not lost. Adding something like alfalfa can be effective and economical.

Other steps you can take include adding further conservation practices that fit your situation. Planting windbreaks can help with water conservation as well as carbon sequestration. Precision nitrogen management is showing promise in conserving nutrients and improving carbon sequestration in the soil. Adding anaerobic methane digesters to a livestock operation will capture methane while providing methane energy and a nutrient fertilizer byproduct.  My message is that most of us seem to have a negative carbon footprint. The practices that we are using today need to be evaluated and re-evaluated.  We all need to start practicing good stewardship. It will take time before we start to see the results of these practices on climate change, but there is no doubt that the effects of climate change on fields and forests on your land is to some degree up to what you do now. My advice is don’t delay.  Help agriculture be a part of the climate change solution.

By: Woody Woodruff