In Population Education we often talk about the relationship between farmland and our growing population. The lesson Earth: the Apple of Our Eye vividly illustrates that only about 4% of our planet is available to grow crops. As we grown in numbers, we continue to stress this very limited resource – we build on land that would otherwise be fertile and what remains is often overused and left to erode away. Fertilizers and pesticides have long been touted as the most effective way to get the most out of our limited cropland. However, the mini-resurgence of an ancient farming practice called cover cropping is now challenging that mindset, not to mention offering a glimmer of hope that our soils just might be savable.
A recent article in the New York Times investigated the topic of cover crops – seeding noncash crops, like rye or sunflower between plantings of more traditional crops, like soy or corn. Rather being harvested, these cover crops are left to decompose and then mix back in with the soil. Though still a long way from being used as a mainstream farming practice, the idea of cover cropping is picking up steam. In fact, researchers estimate that the number of acres planted with cover crops has nearly doubled in the last four years.
When you consider the benefits, it’s no surprise that this method is growing in popularity. Soil that has been seeded with cover crops is more resistant to erosion and also has higher carbon content, making it significantly more productive than traditional mono-culture soil. For example, one farmer in Indiana noticed that after planting cover crops, the water that ran off his once eroding field was clear, a “sign that the roots of the cover crops were anchoring valuable topsoil in place.” (For a detailed explanation of how cover crops prevent erosion, watch this quick video!) Cover cropping also adds necessary carbon back into the soil – carbon that has been removed from years of cultivation. In short, when cover crops decompose, they leave behind rich organic matter that boosts the overall health and productivity of the field. This works so well, in fact, that farmers who use cover crops have found that they no longer need to use fertilizers and can significantly decrease their use of herbicides. Considering the harmful effects of fertilizer runoff, this is a win-win for both the farmer and the surrounding environment.
Farmers across the country are also slowly realizing that long term soil health goes hand in hand with increased profit. One farmer estimated that despite spending money to buy cover seeds, he netted an extra $107,000 a year in part because of higher yields, but also because he no longer needed to purchase fertilizers and other chemicals. This shift in thinking spells good news for the future of our farms and in turn, humanity. We hope that the practice continues to spread and that our soils will reap the benefits for years to come.