Seed Grant: No-Till Farming and Methane Removal
Croplands can be net emitters or biological sinks for greenhouse gases depending on land-use and management practices. Land use change and agricultural activities contribute an estimated 25%, 60-65% and 90% of the total anthropogenic carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4 — a major greenhouse gas) emissions, respectively. In recent years, numerous assessments have been made to evaluate the potential of croplands to offset greenhouse gases emissions from the energy and industrial sectors. No-tillage farming, a way of producing crops without any tilling of the soil, figures prominently among the management practices recommended for that purpose. However, most attention has been on the impact of no-tillage to remove CO2 from the atmosphere and to sequester carbon in soils. Major uncertainties remain with regard to the impact of no-tillage farming on other greenhouse gases.
Ohio has an internationally recognized history and expertise in researching and promoting no- tillage agriculture. The longest continuously maintained no-tillage plots in the world are in Ohio and these plots have been very important in making important discoveries about the interaction of soils, crops, climate and tillage for almost 50 years. Although long-term no-tillage farming is expected to be beneficial to CH4 oxidation, and thus its removal from the atmosphere, this remains a working hypothesis and experimental data are needed to assess its validity.
In order for our science to continue to inform our policy decisions, it is critical that we generate accurate CH4 removal rates for no-tillage systems. This information will also be useful in promoting better modeling, at landscape scale levels, of the impact of no-tillage on the fate of methane. No-tillage agriculture is currently being practiced on about 25% of all farmland in the United States and estimates are that as more marginal lands are put into production to boost production of food and other raw materials, this percentage will increase.
The main hypothesis of our research is that the longer no-tillage is continuously applied to a soil, the greater becomes the soil's ability and potential to oxidize CH4, thus removing CH4's greenhouse warming impact. We therefore propose to conduct a study using no-tillage croplands of different ages, but on similar soil types and in the same eco-region, in order to isolate the impact of tillage from other factors on soil CH4 oxidation and atmospheric removal.
Work has been initiated on building chambers to install in no-tillage fields for sampling of CH4. We are in contact with several farmer cooperators to discuss research on actual no-tillage farm fields.
While this Seed Grant was in preparation and also while it was being reviewed, a video was created to provide information about no-tillage agriculture and how it can have an important role in controlling the levels of greenhouse gases in the atmosphere.
School of Environment and Natural Resources
College of Food, Agricultural and Environmental Sciences