South Dakota Farmer Harvests Sunlight

In addition to harvesting corn and soybeans, one South Dakota farmer says he’s “harvesting sunlight.”

Paul Hetland, who farms near Mount Vernon, uses a variety of farming practices to promote soil health on his acres, including cover crops.

Planted following harvest, cover crops on Hetland’s farm are typically a mixture of brassicas, legumes and grasses. They add nutrients to the soil and help protect it from wind and water.

“Our goal is to have something growing as many days out of the year as possible,” Hetland says. “We think of it as harvesting sunlight.”

Sequestering Carbon

“We’re trying to put carbon in the soil,” says Hetland. “And those plants, if you think of them just taking that sunlight and pumping it into the ground, that’s kind of the way I look at it,” he says.

“The plants are converting that sunlight, and they are releasing the extrudes through their roots to feed the biology within the soil. And as those plants die off or as that biology dies off, that turns into fertility and nutrients for subsequent crops.”

Agriculture, like many other systems, is carbon-based.

“Through the grasses that we plant, we are sequestering carbon in our soil that is not released,” Hetland says.

He tries to minimize tillage and soil disturbances to avoid putting the carbon back into the atmosphere.

“We’re keeping the carbon in our system where we can utilize it. And it just creates this huge resource for us to produce these higher yields that we’re trying to build as we make our soil more healthy,” he adds.

What Is Healthy Soil?

Farmers statewide are focusing on building healthy soils in their fields.

It’s partly because healthier soil delivers improved yields. But it’s also about playing the long game. Farmers work today to build soil health to benefit future generations tomorrow.

“To me, the ultimate measure of healthy soil is the output it produces,” Hetland says. “But along the way, we measure healthy soil by the way it absorbs water.”

“Healthy soil allows us to plant a crop successfully under less than desirable conditions,” he says. “It supports traffic. It gives us nutrients so we can reduce our use of commercial fertilizers. It mineralizes and recycles nutrients for us. It just is a system that allows our business to be more profitable.”

Some farmers assess soil health by looking at the percentage of organic matter in their soil.

“I think organic matter is certainly a good measure, and it’s something that we start with,” says Hetland. “Generally speaking, the higher your organic matter is, the more productive that soil can be. It holds more water. It releases more nutrients. So, organic matter is a great start.”

“There are physical properties that we look for, as well,” he says. “We see whether the soil clumps, whether we can close a furrow behind the tractorto give us seed-to-soil contact in the spring and things of that nature.”

In addition to improving soil health, Hetland’s farming practices also help reduce the use of commercial fertilizers and weed control products.

“In essence, we’re creating a system where we’re producing more with less,” he says.

  • Twenty years ago, U.S. farmers were feeding an average of 85 people each. Today that number has jumped to 155.
  • Over the last 20 years, U.S. corn production grew 80 percent, while:
    • Land use decreased by 37 percent.
    • Soil loss decreased by 69 percent.
    • Energy use decreased by 37 percent.
    • Emissions per bushel decreased 30 percent.
  • Growers raise 70 percent more corn per pound of fertilizer than 35 years ago.
  • Farmers today grow five times more corn than they did in the 1930s.
  • The average yield per acre has grown from 24 bushels in 1931 to 164 today. Contest winners have averaged over 600 bushels per acre.
  • Reduced tillage prevents erosion. Its adoption in South Dakota has increased from less than five percent in 1985 to 35 percent in 2010.
  • One acre of corn removes eight tons of greenhouse gases.
  • Thanks to ongoing innovations in seed, equipment and fertilizer technology, the amount of emissions per bushel generated to produce corn fell 30 percent in the last 20 years.
  • Farmers use Global Positioning System (GPS) technology to guide equipment so overlapping doesn’t occur.

Scientists have proven that corn grown in South Dakota actually adds carbon to the soil by virtue of the unique Northern Plains climate and increased use of minimum tillage practices by farmers.

  • Over the 25 years of the study, South Dakota corn average yields have increased at a rate of 2.29 bushels per acre per year.
  • Higher yields mean more crop residue left behind. The increased amount of residue has a significant impact in building soil carbon.
  • Our cooler Northern Plains climate plays a key role in the equation due to mineralization, a process by which organic matter and humus break down in the soil. When there are cooler temperatures, the mineralization rates are lower.
  • No-tillage adoption in South Dakota has increased from less than five percent in 1985 to 35 percent in 2010. Minimum and no-tillage production means there is more residue left behind in cornfields. Those practices also mean fewer trips across a field, resulting in even greater environmental benefits.

South Dakota farmers are protecting natural resources.

  • Advances in seed science, machinery and precision farming tools help farmers grow more with simplified weed control and reduced chemical applications.
  • One acre of corn removes eight tons of harmful greenhouse gas, more than what is produced by your car annually.
  • Because of innovative fertilizer application methods and frequent soil testing, American farmers grow 87 percent more corn per ounce of fertilizer.
  • Planting cover crops and/or moving to longer crop rotations allows farmers to naturally manage soil fertility, quality, water, weeds and pests – and improve farm habitat for wildlife.

Reduced tillage conserves soil.

  • Reduced or no-till planting conserves soil and water and reduces soil erosion and fuel usage.
  • No-tillage adoption in South Dakota has increased from less than five percent in 1985 to 35 percent in 2010.
  • Reduced tillage and other farm management practices have decreased soil erosion by 37 percent in 20 years.

South Dakota farmers protect water quality.

  • Farmers work hard to protect streams, ponds, rivers, lakes and wetlands. By keeping water edges in their natural state, we help control runoff and erosion and allow water insects, animals and fish to thrive.
  • Cover cropping helps reduce soil erosion.
  • Natural vegetation “filter strips” intercept and trap pollutants and soil from fields before they reach waterways.
  • Furrow alignment reduces the amount of runoff from rain or irrigation.
  • Diversion channels send runoff to safe areas and prevent excessive erosion.
  • Buffer strips and grass waterways in ditches capture sediments or nutrients and prevent erosion.

Drain tiling in a field is similar to drainage around your home — diverting water where it is not wanted. It’s a way to manage excess water and to keep nutrients in the fields. Tiling helps with:

  • Reducing storm water runoff and downstream flooding through absorption.
  • Reducing water damage to public roads.
  • Decreasing crop loss due to drowning.
  • Increasing soil surface temperatures, which helps seeds germinate.
  • Allowing plant roots to grow deeper into the soil so they can absorb more nutrients.
  • Providing enough oxygen for plant roots to mature properly.
  • Increasing the number of days available for planting and harvesting crops.
  • Improving soil structure by avoiding soil compaction and structural damage.
  • Promoting energy-conserving farming practices such as no-till and conservation tillage.
  • Reducing loss of sediment and nutrients.
  • Allowing for more efficient use of resources.