As farmers, one of the things that may have crossed your mind a time or two is the availability of food-producing land of high quality—good, arable land for all your crops. Scientists at University of Sheffield’s Grantham Centre for Sustainable Futures have been thinking about that too. They’ve discovered that the “world has lost a third of its arable land due to erosion or pollution in the past 40 years” and the consequences could be disastrous because the loss rate is much faster than “the pace of natural processes to replace diminished soil,” The Guardian reports. In fact, erosion is occurring 100 times faster than the creation of new topsoil.
The study was conducted by analyzing various publications of research from the last 10 years. The researchers found that “continual ploughing of fields, combined with heavy use of fertilizers, has degraded soils across the world.”
One of the researchers of the study, Duncan Cameron, is a University of Sheffield plant and soil biology professor. He told The Guardian, “You think of the dust bowl of the 1930s in North America and then you realize we are moving towards that situation if we don’t do something. We are increasing the rate of loss and we are reducing soils to their bare mineral components. We are creating soils that aren’t fit for anything except for holding a plant up. The soils are silting up river systems – if you look at the huge brown stain in the ocean where the Amazon deposits soil, you realize how much we are accelerating that process. We aren’t quite at the tipping point yet, but we need to do something about it. We are up against it if we are to reverse this decline.”
The biggest cause of the soil erosion, according to the study, is the constant planting and harvesting of crops. When soil is turned over again and again, its exposure to oxygen causes the release of its carbon, making its binding less effective. Once the soils have become degraded in this way, it is more likely to be washed away with rain.
Unfortunately, this decline in soil is happening at the same time that there’s an increase in the world’s food demand. The Guardian reports that 50 percent more food needs to be grown worldwide to feed the nine billion people that’s anticipated by 2050.
“We need a radical solution, which is to re-engineer our agricultural system. We need to take land out of production for a long time to allow soil carbon to rebuild and become stable. We already have lots of land – it’s being used for pasture by the meat and dairy industries. Rather than keep it separated, we need to bring it into rotation, so that that there is more land in the system and less is being used at any one time,” Cameron told The Guardian. “We can’t blame the farmers in this. We need to provide the capitalization to help them rather than say, ‘Here’s a new policy, go and do it. “We have the technology. We just need the political will to give us a fighting chance of solving this problem.”
The researchers are presenting their study and findings at the 2015 climate talks in Paris.