Cover Crops; Research Continues

Cover crops have been around for a long time. Until recent years, no one gave them much thought. That is changing.

According to Ann Ronning, Roosevelt County Extension Agent, the concept of cover crops dates back hundreds of years. “It really went by the wayside after WWII with the development of synthetic fertilizers and chemicals. Prior to the War, cover crops were used to help prevent soil erosion and to add fertility to the soil,” she said.

Today, researchers are looking at the potential benefits of going back to natural solutions. In Northeast Montana, research is underway.

In a joint two-year project on cover crops between the Eastern Ag Research Center, Sidney, and MSU Northern Ag Research Center, hHavre, Mont, experts are gauging the potential benefits of incorporating cover crops into the family farm crop rotation during the time they would normally leave the land bare.

The project is being funded through the Natural Resources Conservation Service.

“We are trying to determine which crops work best by combining varying cocktail blends of legumes, cereals, root crops and others to see which ones have the best potential for aiding in soil health while increasing biomass,” said Dr. Darren Boss, Montana State University NARC Superintendant and Beef Specialist.

The research is taking place near Havre using 16 different cover crop mixtures of radish, oats, turnips, barley and legumes that encompass warm, cool and warm/cool blend species planted and terminated in three different ways. Some are terminated with chemical, some are swathed and baled for cattle and some are grazed with steers. This will help determine how the crops interact with the soil and how next year’s spring and winter wheat protein and test weights look after being planted directly behind the cover crop.

There is also additional research being conducted at the Froid Research Farm with the EARC, in Sidney.

The goal of cover cropping is to avoid bare soil between cash crop plantings.

Cover crops are generally grouped according to their botanical classification. Two groups of plants, grasses and legumes, account for most of the plant species used in lieu of fallow. But, there are other excellent crops that do not fall into these categories that offer a wide range of benefits to a farming system, including mustards, forage radishes and sunflowers.

So, what exactly are the best cover crop mixtures for farmers in Northeast Montana looking for ground coverage year round? That’s still debatable. The truth is, while some experts have some ideas about what crops handle the dry, arid conditions best, the research behind it is still underway. Yet, crops that predominately do well in the area that require shorter growing periods or are more acclimated to the harsher conditions such as peas, lentils, millet, turnips, radishes, soybeans and safflower may be some good cover crop choices.

Boss said that while most farmers in the Golden Triangle still rotate their crops with fallow, some are beginning to look into the potential benefits of cover crops for grazing and haying as well as improving the health of the soil by increasing organic matter. In Northeast Montana, very few farmers are experimenting with cover crops.

When determining what to plant as a cover crop, experts say a mixture is best because each species does something different to the soil. Legumes will fixate nitrogen into the soil, broadleaves will add nitrogen as they decompose, turnips and radishes will break up the soil adding air and organic matter. Cereals can break disease cycles and root crops can also open fissures for more moisture penetration.

Successful use of cover crops can offer many benefits such as reducing the impact of wind and water passing over the soil surface to reduce erosion. It can improve the condition of the soil and suppress weeds because it competes for light, water and nutrients. It can also provide a diverse cropping system that creates habitat for animals and beneficial insects.

Side benefits can even include improved trafficability of fields and reduced compaction, enhanced aesthetics and potential for animal feed production. Improved soil, over time, may improve crop yields, leaving the farmer with higher profits as well.

“When selecting a cover crop mixture it should include warm season grasses, cool season grasses, warm season broadleaves, cool season broadleaves and legumes,” Ronning said.

Obviously, no one cover crop is going to accomplish all of those goals, or even a majority of them. It’s up to farmers to study the situation in their fields and decide what they want to accomplish because each of the specific potential benefits requires a different seeding program. Next, they need to plan the specific planting time, the specific type of cover crop, and the specific harvest method and time to end the cover crop.

Farmers also should consider the challenges of cover crops, expense and the extra time in the field required.

There are some challenges to replacing fallow with cover crops. First, there is a lack of moisture in the growing season especially late in the season. Secondly, if the cover crop is planted following another crop, there is a shortened growing season ahead of cold temperatures.

“After all of this research we may find out that cover crops are not a good fit for this area. In the past two years since that this research began, this area has experienced unique weather conditions that may be attributable to cover crops success,” Boss said.

On average this area receives 12 to 14 inches of precipitation a year.

“The moral of the story is that after all of this research, whether or not cover crops are a good fit for Montana will boil down to water use and deep soil moisture. It is always easier to take fertilizer and soil to plants than it is water,” Boss said.