Soil Health Boosts Corn and Soybean Yields

Reduced Tillage and Better Soil Health Improves Yearly Yield

Corn and soybean yields have steadily increased across the Midwest since 2000, according to a study by South Dakota State University. Researchers found corn yields rose by over two bushels per acre annually, while soybeans increased by more than half a bushel. 

This growth is due to better crop varieties and improved soil health. Conservation practices like reduced or no-tillage have helped raise soil organic matter by over 650 pounds per acre yearly. These changes help store water, hold nutrients, and support healthy crops. 

Historically, farmers used deep tillage methods that harmed the soil, especially during the Dust Bowl. But today, many use no-till or reduced tillage methods. By 2021, nearly 77% of eastern South Dakota farmers had adopted these approaches. 

Researchers used over 650,000 soil samples collected from 2000 to 2021. They discovered South Dakota fields stored 428 pounds of carbon per acre each year. Across four Midwestern states, 1.24 billion metric tons of carbon were stored during this time. 

As soil carbon levels rise, less nitrogen fertilizer is needed. In South Dakota, nitrogen use dropped by 25% without lowering corn yields. Better soil also helps farms withstand droughts. In 2012, improved soil saved South Dakota $1.1 billion during a severe drought. 

The study proves that healthier soil and modern farming methods create a loop: better soil increases yields, and higher yields improve the soil. While carbon saturation may happen one day, current levels show soil can still store more. 

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