Overly acidic soils can mean the difference between feeding a region and famine. Each crop needs the right soil pH to thrive, and acidic conditions, produced primarily by industrial emissions and application of fertilizers, can harm growing conditions. It has recently been estimated that sub-Saharan Africa, for example, loses billions of dollars annually in crop yield because of poor agricultural conditions. But there is a possible solution and it could even help the Earth’s climate.
For centuries, farmers have neutralized soil acidity with a practice called liming. It involves mixing crushed calcium- or magnesium-rich rocks, known as limestone, into the soil to balance pH. But liming has long been an assumed tradeoff in which removing acid also meant increasing carbon emissions into the atmosphere.
New research from Georgia Tech shows that the opposite may be true. Agricultural liming can actually reduce atmospheric carbon dioxide and improve crop yield.
“The current thinking about liming is that farmers must choose between doing something that could benefit them economically or reducing their greenhouse gas emissions,” said Chris Reinhard, an associate professor in the School of Earth and Atmospheric Sciences. “But this is often a false choice. They can do both.”