"Marginal improvements to agricultural soils around the world would store enough carbon to keep the world within 1.5C of global heating, new research suggests.
Farming techniques that improve long-term fertility and yields can also help to store more carbon in soils but are often ignored in favor of intensive techniques using large amounts of artificial fertilizer, much of it wasted, that can increase greenhouse gas emissions.
Using better farming techniques to store 1 percent more carbon in about half of the world’s agricultural soils would be enough to absorb about 31 gigatons of carbon dioxide a year, according to new data. That amount is not far off the 32 gigaton gap between current planned emissions reduction globally per year and the amount of carbon that must be cut by 2030 to stay within 1.5C.
The estimates were carried out by Jacqueline McGlade, the former chief scientist at the UN environment program and former executive director of the European Environment Agency. She found that storing more carbon in the top 30 centimeters of agricultural soils would be feasible in many regions where soils are currently degraded.
McGlade now leads a commercial organization that sells soil data to farmers. Downforce Technologies uses publicly available global data, satellite images, and lidar to assess in detail how much carbon is stored in soils, which can now be done down to the level of individual fields.
“Outside the farming sector, people do not understand how important soils are to the climate,” said McGlade. “Changing farming could make soils carbon negative, making them absorb carbon, and reducing the cost of farming.”
She said farmers could face a short-term cost while they changed their methods, away from the overuse of artificial fertilizer, but after a transition period of two to three years their yields would improve and their soils would be much healthier...
Arable farmers could sequester more carbon within their soils by changing their crop rotation, planting cover crops such as clover, or using direct drilling, which allows crops to be planted without the need for ploughing. Livestock farmers could improve their soils by growing more native grasses.
Hedgerows also help to sequester carbon in the soil, because they have large underground networks of mycorrhizal fungi and microbes that can extend meters into the field. Farmers have spent decades removing hedgerows to make intensive farming easier, but restoring them, and maintaining existing hedgerows, would improve biodiversity, reduce the erosion of topsoil, and help to stop harmful agricultural runoff, which is a key polluter of rivers."
-via The Grist, July 8, 2023
