Use of Cover Crops Continues to Grow

After harvest, many fields in Iowa are greening up again.  And it’s not weeds.  More and more farmers are planting cover crops to protect their soil from erosion and recycle nutrients.  This improves soil health and can lead to greater profitability through increased yields and decreased inputs such as fertilizers and

The popularity of cover crops has really taken off.  In August, as part of Iowa’s new Water Quality Initiative, over 1,000 farmers across every county in Iowa signed up for cost share to plant over 100,000 acres of cover crops.  This tremendous response is estimated to more than double the amount of cover crops that were planted last year.

The increased use of cover crops is extremely important as Iowa implements the Water Quality Initiative as part of the Nutrient Reduction Strategy that was released in May.  The strategy seeks to improve Iowa water quality and reduce the dead zone in the Gulf of Mexico by reducing nutrient losses by 45%.  The science assessment that was done to support the strategy indicates that cover crops can reduce losses of nitrogen and phosphorus by approximately 30%.  By reducing nutrient loss, more nutrients are available for next year’s crop which can increase yields and decrease fertilizer inputs.

Many cover crops can be hayed or grazed.  The vegetation protects the soil from erosion and also suppresses weeds.  The roots and foliage can increase organic matter which increases water infiltration.  More water infiltration reduces runoff and flooding and also can recharge subsoil moisture for droughts.

Incorporating cover crops into cropping rotations means changes in crop management.  Tillage, fertilizer, herbicides, and planting dates may need adjustments.  Cover crops need to be planted early enough in the fall to allow for germination and growth.  Aerial seeding can help with this.  They need to be terminated in the spring to prevent interference with the next corn or soybean crop.  This can be accomplished by grazing, haying, tilling, spraying, or a combination of these.

Financial and technical assistance is available from many sources such as soil and water conservation districts, extension, and crop advisors.  There are multiple field days across the state this fall and spring where farmers can learn from other farmers who are using cover crops (www.iowacorn.org/en/news/upcoming_events ).  Many farmers who use cover crops started off slowly by experimenting on a small field and applying the results of their experiments as they expanded their acres.  Don’t get left behind as use of cover crops continues to grow!