Grazing cows emit less nitrous oxide than assumed

Agriculture is responsible for about two-thirds of nitrous oxide emissions in Switzerland Keystone / Arno Balzarini

Grazing cows emit less environmentally harmful nitrous oxide than previously thought, according to researchers from Swiss agricultural research centre Agroscope.

Agriculture is responsible for about two-thirds of nitrous oxide emissions in Switzerland, Agroscope wrote on Wednesday. However, the climate-warming effect of nitrous oxide is about 265 times stronger than that of carbon dioxide.

Only about 5% of nitrous oxide emissions from agriculture come from grazing cows. This is significantly less than previously calculated or even estimated, said Christof Ammann from Agroscope in a videoExternal link recorded on the research pasture in canton Thurgau, northeastern Switzerland.

The trial on the pasture near Tänikon has been running for two years. Ammann explains how various devices are used to measure the concentration of nitrous oxide and other greenhouse gases in the air and on the ground. The emissions are calculated from this. Cameras are used to monitor how many cows are in the measuring sector.

How much nitrous oxide grazing cows actually emit depends on the conditions on site, namely the soil and the humidity. In dry years, emissions were lower than in wet years. The new guideline values are now to be incorporated into emission inventories, such as the environment ministry’s greenhouse gas inventory.