Ongoing climate change constitutes a threat to the future food supply. In Sweden, global warming is expected to lead to a longer growing season but also to more varied weather, with an increased risk of extreme weather events, which could negatively impact harvests. Increasing the resilience of agriculture in a future climate is therefore crucial to food security.
Higher level of carbon increase the resilience
Now, researchers at the AgriFood Economics Centre and the Centre for Environmental and Climate Science (CEC) at Lund University have investigated whether a higher level of carbon in the soil could increase the resilience of agriculture – and the answer is yes.
“We show that using land in a way that preserves or stores more carbon in the soil makes crops more resistant to the weather variations that future climate change is expected to bring, such as higher temperatures with more frequent periods of drought, but also longer periods of heavy precipitation”, says Mark Brady, associate professor in natural resource and environmental economics at AgriFood/Swedish University of Agricultural Sciences and CEC.
Researchers already knew that a high carbon content in agricultural soil is associated with better water retention, more nutrients and a lower risk of soil compaction and erosion. They also knew that the moment in a crop’s growth period at which an extreme weather event occurs is significant. However, no one had yet investigated how these factors interact, which the researchers examined in the case of wheat and barley. For wheat, the results show that a higher carbon content is beneficial under all circumstances, whereas it only benefits barley under particular conditions.
Targeted environmental payments may be required
“Overall, however, it is clear that agricultural practices that preserve or increase carbon in the soil, for example periods with grass pasture growth or cover crops, can function as insurance for future harvests”, says Mark Brady. Instead, several common agricultural practices currently in use, with highly intensive use and deep cultivation of the soil, deplete soil carbon. Converting to other methods would though be costly for many farmers in the short term.
“That is why targeted environmental payments for farmers may be required for a time, to facilitate the transition to more soil-friendly agricultural methods, as the environmental compensation from existing schemes is generally too low to attract any great interest”, says Mark Brady.
He points out that increased carbon sequestration in the soil would also reduce the climate impact of agriculture, resulting in multiple gains from more soil-friendly farming methods.
The AgriFood Economics Centre is a collaboration between the School of Economics and Management at Lund University and the Swedish University of Agricultural Sciences.