A study by UC Berkeley’s Agroecology Lab on cover cropping revealed findings that show implementation of this practice in farms during their off season could mitigate carbon emissions.

Cover cropping is when crops are put on top of the soil during the “off season” of farming. It has been shown to decrease carbon output, according to Isaac Vendig, a campus researcher and study co-author. He added that as a result, cover cropping is growing immensely in popularity among researchers who are trying to solve the climate crisis.

“While cover crops are in the ground, they can also nourish soil microbial communities and fix nitrogen from the air (rather than using artificial fertilizer), improving the soil in many ways,” said Alastair Iles, campus professor of sustainability transitions, in an email. “Cover crops can also protect farm fields that would otherwise be barren during off-growth periods.”

According to Iles, the lab’s research discovered that in addition to cover cropping showing promising results for the decrease in carbon emissions, it also showed an increase in crop yield by about 60%.

Iles noted that using cover crops such as crimson clover, legumes, hairy vetch, field peas and subterranean clover led to these increases in yields and soil organic content.

“There is still no consensus about the effects of cover cropping on yields and especially the more detailed differences between when cover cropping is used in a monocrop corn system versus corn soy,” Vendig said.

Vendig explained that this research was inspired by previous papers exploring organic carbon and yields that focused on the limitations and prior lack of consensus regarding approaches that could cause significant change in reducing carbon emissions.

Experts from both UC Cooperative Extension and federal Natural Resource Conservation Services can advise farmers to change their growing practices in hopes for California farmers to adapt in response to climate change, according to Iles. Before cover crops are implemented in California farms, Iles said this new research will hopefully increase legislative awareness for future implementation.

“The study can also inform the California state legislature to put more money into the Healthy Soils Program, which makes grants to farmers statewide to use many kinds of practices that build soils, including cover crops,” Iles said in an email.

Vendig also noted that there needed to be policy changes, but included that farmers need to also be given economic incentives in order to make those changes on their farms.

Vendig emphasized the benefit of cover cropping and how that can be used to make changes in carbon emissions.

“What we did find specifically with cover cropping is that whether or not there is a direct connection between organic carbon and yields, you can still find these situations in which cover cropping can provide pretty substantial yield benefits, and at the same time it provides some fairly decent organic carbon increases,” Vendig said.