Now, many farmers do not till their fields, but this increases fertilizer run-off. Also, when soil bacteria finds a tasty combination of nitrogen fertilizer and oxygen on the surface, they eat it up and release nitrous oxide.
The university researchers experimented with the technique of tilling strips of the field about a foot wide and eight to nine inches deep. This allows farmers to use less gas in their tractors while still leaving crop residues, like corn stalks, on the field's surface to prevent erosion.
When farmers till strips and apply fertilizer into the soil of the furrows, the nitrogen fertilizers don't run off and pollute waterways. It also improves yield since more fertilizer gets to the plants.
Here's where the climate benefits come in. By placing the nitrogen fertilizer into the furrows, less of the chemical is converted into nitrous oxide by air-breathing soil microbes.
The researchers conducted their study in northeast Missouri from 2008 to 2010. One field was "strip tilled" with nitrogen fertilizer placed in a band in the soil, while another field was left untilled with a surface application of nitrogen fertilizer.