UPDATE: CLICK HERE to download the fall 2018 Forage + Cover Crop Management Guide.
CLICK HERE to download the fall 2017 Forage + Cover Crop Management Guide.
Cover crop use has been rapidly growing since 2000. The row crop acreages planted in cover crops have been growing about 30% per year, which equals hundreds of thousands of acres of growth per year. The science behind covers crops is still developing, but there is much already known - enough is known that agronomists are absolutely comfortable recommending cover crops.
While there are still many things we don't know about cover crops, we certainly know enough to understand numerous agronomic benefits and the resulting increased net profits. Cover crop users have been regularly gaining $50/acre net profit, with a $100/acre increase in profitability common. How does a cover crop increase cash crop profits?
Break Soil Compaction: Many cover crop species, such as radishes and annual ryegrass, are known for deep-penetrating root systems. Deep roots can successfully break up hardpans. The following cash crop can then grow deeper root systems that result in more drought tolerant crops. Furthermore, the additional root-growing zone opens up more nutrients for the cash crop.
Disease Control: Many cover crop species suppress common diseases found in cash crops. For example, the Ohio State University has shown that annual ryegrass can virtually eliminate soybean cyst nematode in fields after just one season, and mustard is a natural biofumigant.
Free Forage: Cover crop species with high forage quality can be selected to generate additional feed or grazing for livestock on fields generally used only for cash crops.
Erosion Control: The typical Midwest farm loses up to 6 tons/acre of topsoil each year to erosion. Other regions also experience significant erosion. And whether by wind or precipitation, erosion in fallow fields is often not noticed. Cover crops keep the most valuable soil on your land.
Improve Soil Health: Mother Nature does not intend for soil to remain fallow. Cover crops contribute to more beneficial microbial and worm activity in the soil.
Increase Organic Content: Cover crops, especially over several years of use, can significantly increase the soil's organic content. Organic content is important for many reason, including increasing water-holding and nutrient-holding capacity. Some types of organic matter can hold up to 20 times its weight in water. A soil high in organic content can be much more productive in drought years, along with helping absorb excess water which can help with timely planting and harvesting. Studies have shown that each 1% increase in soil organic matter is worth more than $500/acre in production benefits.
Increase Soil Temperatures: A study by the University of Maryland found spring soil temperatures were 6 to 8 degrees F warmer following a radish cover crop compared to a fallow field. Other species likely also help with more rapid spring soil warming. Warmer spring soils allow for quicker germination and faster early season crop growth.
Nutrient Storage/Production: Cover crops can be very effective in absorbing nutrients remaining after a cash crop harvest. A large percentage of those nutrients are held in the cover crop plant and then released when the cover crop is terminated. When left fallow, a significant amount of those nutrients can leach out of the soil and are lost. Some species help free up micronutrients for cash crops to utilize. Legume cover crops can produce nitrogen for the next cash crop to utilize.
Suppress Weeds: Most of the well-known cover crop species and properly formulated mixes are excellent at suppressing weed control, resulting in decreased herbicide use.
CLICK HERE for a PDF with more details on cover crop agronomics.
When all the benefits are added together, fewer inputs are needed, crops are more drought tolerant, soil health is better, planting and harvesting times can be more timely, and additional forage can be produced. These benefits are very real and have been proven time after time in large-scale, side-by-side trials. Some growers that have embraced cover crops have even reported increased net profits of $200/acre. These growers report corn yields that have increased up to 50 bushels/acre and soybean yields up by as much as 20 bushels/acre.
CLICK HERE to view the amazing results of an annual ryegrass cover crop study in Illinois. While newer annual ryegrass products are now available, such as Perforate, the improved cash crop yield is the remarkable aspect of the study.
CLICK HERE to view a fascinating and informative video by Doug Peterson, Missouri NRCS State Soil Conservationist, on the effects cover crops have on soil water infiltration and erosion.
CLICK HERE to review the latest cover crop species chart from the USDA. The tool provides good info on most cover crop options.