Climate-smart agriculture in Wisconsin
It has been more than ten years since the first Wisconsin Initiative on Climate Change Impacts (WICCI) report was published in 2011. During the intervening years, the atmospheric concentration of CO2, the most important driver of climate change, has climbed above 400 parts per million (ppm) for the first time in four million years.
The last time that CO2 was at its current level (420 ppm at time of writing) the global average temperature was 5.4 degrees Fahrenheit hotter, sea levels were close to 100 feet higher than today, and the Arctic was free of ice. While we are still a long way from a Pliocene-era climate, recent trends towards shorter, warmer winters and more concentrated precipitation show that our climate has already changed, and those changes are expected to intensify.
This past year, in tandem with the release of the second WICCI report, an extensive report from the Agriculture Working Group detailed agriculture’s contributions to greenhouse gas emissions and climate change, the impacts of climate change on Wisconsin agriculture, and ways farmers can adapt to the changing climate.
While agriculture plays a fundamental economic and cultural role in America’s Dairyland, it also accounts for 15% of the state’s total greenhouse gas emissions. Although Wisconsin’s total greenhouse gas emissions fell by 9% between 2005 and 2017, our agriculture sector increased its emissions by 14.3%.
The report dives into the specifics on how the effects of climate change will be felt across Wisconsin’s diverse agricultural landscape. For example: “increased warming in the spring and fall can extend the growing season for summer crops like corn, beans, and alfalfa, but warming in summer could push temperatures outside the optimal range for some crops like potatoes,” while “increased winter temperatures could reduce the formation of ice and chilling units that cranberries need.”
The Agriculture Working Group’s report identifies four key strategies for reducing the sector’s contribution to climate change and increasing overall agricultural resilience:
- Increasing continuous living cover on agricultural land has the potential to reduce the need for nitrogen fertilizer applications and associated emissions of nitrous oxide (a very potent greenhouse gas). Continuous living cover can also increase soil carbon storage. In particular, rotationally managed pasture needs less nitrogen fertilizer than corn and stores more soil carbon than overgrazed pasture or annual cropland. (Land in continuous living cover can also better handle intense rainfall events, especially in winter and spring.)
- Avoiding conversion of grasslands and other natural landscapes to row crop production, and avoiding conversion of agricultural land to development will prevent further loss of carbon stored in soils and trees to the atmosphere.
- Improving manure management to reduce liquid manure storage and better align nutrient application rates with plant nutrient need can reduce methane emissions from manure and nitrous oxide emissions from soils.
- Increasing nitrogen use efficiency can reduce nitrous oxide emissions from soils and reduce carbon dioxide and methane emissions from fertilizer production.
The ability of some agricultural adaptations to climate change to also mitigate greenhouse gas emissions highlights the integrated nature of the climate system. In order to meet the needs of agriculture in a changing climate, we too must adapt and adopt a systems approach to thinking about agriculture.
The current soil health movement is a first step in the right direction. Grounding these interconnected ecological systems within something tangible, the soil, where we can see the structures built by practices like continuous living cover and reduced tillage, provides a practical pathway to seeing the whole. Using the soil ecosystem as a point of departure, subsequent articles drawing on the Agriculture Working Group's report will give a more detailed look at the future of climate-smart agriculture in Wisconsin.
Fulwider is the regional crops educator for the Dane and Dodge County Extension