In 2017, there were 23,300,000 acres planted to corn and soybeans in Iowa. Over half of these acres spent 5-6 months bare and vulnerable to erosion. On our pursuit to be better stewards of the land, we must do better at protecting the soil that funds our livelihoods. One way to accomplish this is through cover crops.
Did you know that is takes 50 years for 1” of topsoil to accumulate? Even more alarming, it only takes one year for that same 1” of topsoil to erode. An established cover crop can help by forming a protective canopy over the exposed topsoil while reducing the chances of erosion. Cover crop’s root systems not only keep the soil in place, but they also take up applied nutrients. Consider it a win-win; the nutrients are stored for the upcoming cash crop to use (maximizing the productivity of your input), as well as keeping the nutrients from mobilizing.
Cover crops also help improve the biological, chemical and physical properties of the soil. If cover crops are used over time, soil organic matter will begin to increase. According to La Crosse Seed, adding diversity and continuous roots to your soil speeds up organic matter gains by .15% annually; even more on healthier soils. Increased organic matter is important because it improves nutrient supply, water holding capacity, and overall soil structure. These soil conditions set the soon-to-be planted crop up for success.
Compacted soil is another common issue across farm land that cover crops can help to alleviate. Poor root structures, limited soil nutrients, as well as plant stress are all outcomes of compaction. Due to the large root masses that some cover crop species have, their roots can penetrate through these compacted areas. Not only does this break up the compacted soil, it returns oxygen and water movement back into the profile. This creates a more ideal seed bed for the crop to come.
Cover crop seeding can easily be incorporated into any operation with a variety of seeding options available. Aerial application, drilling, and incorporating seed with fall fertilizer are among some of the most popular. Growing in popularity with our customers is the Valmar 56 series applicators. A common pairing is the Valmar mounted onto fall tillage equipment. This creates an easy and efficient application method that saves time while reducing field passes and equipment hours.
Although there are numerous benefits to cover crops, it’s important to consider all factors. Seed, along with application, is just the beginning of the added cost. Just like anything else in agriculture, weather is our biggest gamble. The worst outcome for any cover crop stand is one that never emerges. It is also important to evaluate the increased threat of insects. Since cover crops are typically the only vegetation available during spring, they are a natural habitat and food source for insects. Once row crops emerge, insects then begin feeding on the new seedlings. To protect your row crops from becoming the next meal, treated seed and/or an insecticide application is crucial.
Cover crops are not a perfect, one-size-fits-all solution for every acre in Iowa. However, too many acres are missing the benefits that cover crops can provide. We challenge you to put a price on your topsoil. How successful can you be once severe erosion plays its part? Topsoil is priceless and realistically, farming without it is challenging. As stewards of the land, we need to do our best to preserve it, regardless of management practice.
“Natural Resources Conservation Service.” Cover Crops – Keeping Soil in Place While Providing Other Benefits | NRCS New York, https://www.nrcs.usda.gov/wps/portal/nrcs/detail/ny/technical/ecoscience/agronomy/?cid=nrcs144p2_027252