This is a transcript of the video.
Aaron Lehman, farmer, Polk County, Iowa: My name is Aaron Lehman. I'm the fifth generation of Lehmans on this farm.
We farm about 550 acres in rural Polk County, Iowa. About 12 years ago, we were farming corn and soybeans, then we started exploring ways to diversify our operation by growing additional crops, and we started exploring growing it organically. In order to grow organically, we were going to need to improve our soil health. We also added the use of cover crops.
Lara Bryant, Soil Health Fellow, NRDC: A cover crop isn't planted to be harvested. It's planted when the soil would normally otherwise be bare, after the cash crop is grown. And it's grown just to protect the soil, keep it on the ground, and keep living roots in the soil.
Lehman: When we started using cover crops, we started seeing a lot of benefits. Our soil tests were showing that we were increasing our organic matter, which adds to soil health and leads to healthier plants.
We're measuring the impact so that we can see our soil fertility build and build, and that'll lead to us using less fertilizers in the future. The other benefits we see is that the cover crops provide protection for our soil so that we don't see any noticeable soil erosion through some of those heavy rains in early spring.
Bryant: A lot of people might not realize that there's a lot at stake if we don't do anything to protect our soil. It filters bad chemicals out so that they don't get into groundwater and surface water.
Agricultural runoff has a lot of nitrogen and phosphorous that comes from fertilizer, and when that gets into the water supply, it can cause drinking water problems, and it can create algal blooms. If we don't invest in cover crops and ways to keep the soil healthy, then water quality will continue to get worse.
Lehman: We started with a small field of only 40 acres, and we tried it and we saw the benefits of it. And we thought, well, let's just try it on another field and another field. Now where we have 450 acres that we're using for cover crops.
Bryant: Cover crops are becoming more popular, but they're still low use, less than 5 percent of cropland. We've been thinking about ways to help farmers grow more cover crops. Just like if a car insurance company rewards a good driver by giving someone a good driver discount, we could give farmers a good stewardship discount by giving farmers a discount on their crop insurance if they plant cover crops.
Lehman: The most common misconception about cover crops is that it's going to lead to reduced yields, and that's a huge concern for farmers.
We're finding that when we use cover crops in the right way, it can actually enhance what we grow and the amount that we grow.
It is one of those situations where you're investing in your farm, you're investing in your fields, and that will pay off in the long run.
Bryant: I think a lot of us take for granted the importance of the soils and how it sustains life on the planet. Without it, we can't have food; it's important for water quality. It performs so many functions that keep us alive.
Lehman: We want to return this farmland to the next generation in better shape than what we found it.
I've got two kids. They might want to be the sixth generation on our farm. This is really what is going to be the source of their livelihood, is a strong farm that's built on thriving soils.
For a healthier backyard garden, you need to invite nature in. Try a few strategies featured in the documentary "The Biggest Little Farm."
A movement to preserve the cultural heritage and organic practices of African American farmers is growing in the Southeast.
Earthworms may seem harmless, but they have the power to transform some of America’s forests—and not in a good way.
A Texas farmer is bucking tradition by putting soil health above all else. The result? Water-retaining, nutrient-rich pay dirt.
Carbon farming, an agricultural movement taking root in Northern California, aims to improve the soil and help stabilize the climate.
Organic farmer Jim Cochran proves that growing nontoxic strawberries isn’t just possible, it’s profitable.
The state’s lawmakers have cut funding for the Leopold Center for Sustainable Agriculture, leaving rural farmers in the lurch.
Molly Rockamann's 14-acre plot in suburban Missouri could be a model for the nation.
You can help rescue the planet’s diminishing agrodiversity . . . even if you’re more of an eater than a grower.
Since this giant salty lake in the desert lost its water supply, its bird habitat has been shrinking and more toxic dust is wafting up from its dry lake bed. Can the Salton Sea be saved?