"Climate-smart soils" may be able to mitigate greenhouse gas emissions by locking away carbon dioxide that would otherwise end up in the atmosphere.
While Earth's soil sequesters a lot of carbon dioxide from the atmosphere, managing farmland appropriately may be a key part of curbing global climate change successfully.
"We can substantially reduce atmospheric carbon by using soil," said Johannes Lehmann, co-author of the recent study and a Cornell University professor of soil and crop sciences. "We have the technology now to begin employing good soil practices to reduce greenhouse gas emissions."
Researchers found that reduced greenhouse gas emissions coupled with prudent agriculture practices can enhance soil productivity and biodiversity, boost crop productivity and reduce erosion, runoff and water pollution. These sustainable practices are believed to improve farms resilience to climate change.
While Earth's atmosphere currently contains about 830 petagrams of carbon, scientists estimate humans add about 10 petagrams each year, largely due to the burning of fossil fuels and industrial or agricultural waste.
However, agricultural soil stores about six times as much atmospheric carbon in organic matter such as manure, roots, fallen leaves and and other pieces of decomposing plants. But researchers said soils have the potential to store even more.
"Improving prediction models, finding 'big data' approaches to integrate land use, soil management and technology to engage land users are key parts to realizing greenhouse gas mitigation from climate-smart agricultural soils," Lehmann added.
For example, one of the mitigation strategies researchers recommended is maintaining the health of native ecosystems and restoring marginal land to ecologically important forests or grasslands.
While there are numerous other sustainable practices - like reducing tillage, improving grazing management, crop rotation or applying biochar - researchers said that it ultimately comes down to farmers choosing the strategy that best suits the land's needs.
However, the study noted that if all Earth's farmers were to manage their fields so the soil could store more carbon, the impacts of annual fossil fuel emissions could be cut by between half and 80 percent.
"The mitigation potential of existing and future soil management practices could be as high as eight petagrams per year," Lehmann concluded. "But how much is achievable depends on the implementation strategies, and socio-economic and policy constraints."
Their study was recently published in the journal Nature.
