A study published  in Scientific Reports reveals that improved agricultural practices could secure a triple win for food security, ecological resilience and climate change – including removing over a billion tonnes of carbon from the atmosphere per year.

In the debate over climate change, agriculture is often seen as part of the problem: agricultural expansion can drive deforestation, and both livestock and chemical fertilisers contribute to emissions of the potent greenhouse gases methane and nitrous oxide. However, the new study shows that simple changes to the management of crop lands around the world could sequester 0.9 to 1.85 billion tonnes of carbon every year for the next 20 years.

“Soils can act as both sources and sinks of carbon” explained lead author Dr Robert ZOMER of the Kunming Institute of Botany, Chinese Academy of Sciences (KIB/CAS). “In fact, if you measure the carbon contained in only the first meter of soil around the world, this global stock of soil carbon is over three times greater than all the carbon stored in the earth’s atmosphere.”

According to the new report, because many agricultural soils have been depleted of their carbon – for example through erosion and intensive tilling - there is massive potential to take carbon out of the air and store it in the earth.

This could be done, the authors say, through the use of low-tech, practical farming methods such as organic manures, mulching, conservation tillage, fertility management, agroforestry (using trees on agricultural land), and rotational grazing.  

“These techniques all increase the amount of organic matter and therefore carbon which is stored in the soil.” explained Dr. Deborah BOSSIO, Lead Soil Scientist at The Nature Conservancy and co-author of the paper. “And unlike other methods for carbon sequestration such as carbon capture and storage, or establishing plant large plantations of fast-growing trees, promoting them would actively help food production and resilience to climate change by improving soil health”.

The research team mapped the sequestration potential of crop soils around the world. Their results showed that the biggest increases in carbon storage would be found in North America, South Asia and Europe. By country, the United States showed the highest total annual potential for increased soil carbon, followed by India, China and Russia.

The new research could have implications for how the international community aims to meet agreed targets for climate change and carbon sequestration. For example, the 4p1000 initiative on Soil for Food Security and Climate aims to sequester approximately 3.5 billion tonnes of carbon annually in soils. The new study suggests that from 26% to 53% of this target could be achieved through improved farming practices.

“Our research reveals a safe, cost-effective route towards significant climate change mitigation” said Dr. Rolf SOMMER, principal soil scientist at the International Centre for Tropical Agriculture (CIAT) and co-author of the paper. “But in order to seize this opportunity, we need to invest in farmers and farming methods which will give us healthier, more productive and more resilient soils”.

The results were presented on Wednesday 15 November at the UN COP23 climate talks currently underway in Bonn, Germany.

Funding for this study was provided by the International Centre for Tropical Agriculture (CIAT) and the CGIAR Research Program on Water, Land and Ecosystems (WLE), with additional support provided by The Nature Conservancy (TNC), the Centre for Mountain Ecosystems Studies (CMES), Kunming Institute of Botany and the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences (Grant Number QYZDY-SSW-SMC014).

Contact:
General Office
Kunming Institute of Botany, CAS
YANG Mei

email: yangmei@mail.kib.ac.cn

(Editor:YANG Mei)