You may have heard, peanuts are healthy. You probably already knew that, but did you know the health of peanuts depends a lot on sustainable farming practices? Farmers consider themselves the original environmentalists, because their livelihoods depend on the viability of the land. Peanuts are a sustainable crop because of their nitrogen-fixing properties that benefit soil and other crops. Now researchers are recommending that farmers plant sod in rotation with peanuts to further improve the sustainability of the land, and the health of America’s favorite nut.
Dr. David Wright, a researcher with the University of Florida, has studied the effects of sod rotation for over 17 years. His research shows that incorporating sod into a crop rotation significantly decreases disease and pest infestations, increases yields, and even reduces the amount of inputs a farmer needs for the crops. It’s all possible because of the restorative soil benefits of organic matter.
The Root of Sod’s Astounding Results
“When most people think of sod they think of a palette of sod or some other grass. What we're referring to is perennial grass,” said Wright. “Whether it's fescue, like they grow up further north, or the bahiagrass or Bermuda grass that we grow here in the Southeast, in the peanut region.” Sod, such as bahiagrass, is a perennial grass that has two-thirds of its biomass below ground. That’s where the soil benefits come into play because it naturally adds organic matter back into the soil.
“The bread basket of our country is the Midwest. It came out of perennial grasses’ high organic matter,” said Wright. “The concept works here in the Southeast too, of building up organic matter and storing more water. It's like putting mulch in your flowerbeds. You know that's going to keep your flowers much healthier.”
According to Wright’s research, increasing organic matter in the soil through sod rotation has shown increases in peanut yields. That’s because the organic matter promotes nutrient and water holding capacity in the soil. Perennial roots penetrate deep below the surface layer, unlike annual crops which only reach shallow depths of the soil near the surface. As a result, crops planted after perennial sod can expand their root depth providing greater access to moisture and nutrients.
Wright compares it to growing a flower in a coffee cup versus a five-gallon pot. The larger vessel will hold more soil moisture than the coffee cup, meaning less watering of the plant. That also means the farmers who rotate crops with sod are able to significantly decrease their use of irrigation and fertilizer. Further, his research suggests that farmers are able to reduce, and in some cases eliminate, their use of pesticides on peanuts planted after sod thanks to the natural pest resistance of perennial grass.
“A lot of reasons for that is that the perennial grasses are, in general, pretty resistant or tolerant to nematodes,” said Wright. “When you have grass in a rotation it can knock down nematode populations. The following crops have much higher yields.” So with all the benefits of incorporating sod into a crop rotation, it seems like all farmers would want to do it.
Sod-based Rotation is Something to Graze On
Unfortunately, it’s not so easy to adopt. Farmers rely on their land to grow crops. Dedicating a portion of that land to grow grass instead of crops might be economically unsustainable for some farmers. That’s why Wright and his team have developed a business model, and are working to communicate cost and benefit analyses for implementing a sod-based rotation.
One solution they’ve researched is including livestock in the farming operation to graze on the sod-sewn field. The cows would also provide natural fertilizer for the field through manure. While cattle ranching is a different animal (pardon the pun) than row-crop farming, Wright says that some 30% of row crop farmers in Florida, Georgia and Alabama already have livestock.
Regardless, Wright sees sod-based rotation as a way to further improve the sustainability of peanuts, the field, and a farmer’s bottom line. “It can contribute to sustainability just from the standpoint that you do have a lot less inputs,” said Wright. “If you’ve got cattle in the system, you’ve got a lot more nutrient recycling. You’ve got deeper roots from not only the summer crops, peanut and cotton, but also the winter crops. In general, we have found that the profit potential maybe two to seven times higher.”
So while your neighborhood lawns may look idle, now you know that perennial grasses are hard at work on peanut farms to help support sustainability.