What are cover crops and how can they benefit your ag operation?
Plants are considered cover crops when they are used to protect and replenish soil. Cover cropping systems have been around for decades but have grown in popularity as more research is done regarding its many benefits. Further research has also reiterated the importance of taking regional differences into consideration during the implementation process.
As of 2017, cover crops in the U.S. totaled 15.4 million acres—a 50 percent increase from 2012. East Coast states have shown the highest percentages of cover crop acreage, which is mainly attributed to higher urban density encouraging optimized production of the croplands that are available.
The benefits of cover crops can vary depending on specific operational need but include,
- Faster drainage;
- Conserves moisture;
- Reduces soil erosion;
- Attracts pollinators;
- Provides weed and pest control;
- Aids traction during harvests; and
- Creates a habitat for beneficial organisms.
Factors to Consider when Choosing Your Cover Crops
To put it simply, there are three main questions to ask when deciding which cover crop to use.
- What region am I planting in?
- What is my goal for these cover crops?
- What time of year am I wanting to plant my crops?
These questions will help you choose the right cover crop seeds for your operation to achieve your desired result.
Additionally, when choosing your crop seeds it’s important to keep in mind that there are four classifications of cover crops (legumes, grasses, brassicas, and non-legume broad leaves) that fall within three seasonal categories (perennials, summer annuals, and winter annuals).
Types of Cover Crops
Legumes are the most popular form of cover crops and are used to fix atmospheric nitrogen, prevent erosion, and add organic matter to soil. They are the least effective at removing excess nitrogen in the atmosphere and suppressing weeds. Legumes are often used in combination with grass cover crops in order to achieve a balance of soil erosion prevention and weed control.
Grasses are a good cover crop to use if you are wanting to add organic matter to the soil. They tend to be higher in carbon which makes it easier to break down soil and suppress weeds. However, they can be a little too good at their job and limit other crops from accessing nitrogen. Grasses such as cereal rye and oats are especially beneficial for erosion control and cattle grazing.
Brassicas are less known but carry unique benefits as a cover crop. They are fast-growing and have strong biomass production which means they can limit fall erosion through the absorption of excess nutrients in the soil. One of the most interesting advantages brassicas hold is their ability to release chemical compounds that are toxic to pathogens and pests within crop soil. While less effective than commercial pesticides, brassicas can be an added protector in terms of pest control management.
Non-legume broad leaves are higher in carbon than their legume counterparts, leading to a stronger ability to break down soil compaction. This is particularly useful when used with a weed-suppressing cover crop such as grasses. Broadleaf non-legumes include spinach, radishes, flax, and more.
Three Seasonal Categories of Cover Crops
Of these four cover crop classifications, each fall within three main categories depending on their growing season.
- Perennials – While cover crops can live for many years without needing to be replanted, it’s important to terminate during harvesting to prevent them from returning as a weed crop.
- Summer Annuals – Cover crops that are seeded in the spring or summer and are usually intolerant to cold although crop residue can linger into winter.
- Winter Annuals – These cover crops are usually planted in the fall and hold sufficient biomass to protect soil through cold temperatures.
Best Cover Crops to Use by Region
Selecting cover crops in the Southeast region of the U.S. is largely reliant on their resilience to warm temperatures and a humid climate. Legumes are often most common in this region, separated by warm and cool types depending on the planting season. Cool season legumes such as hairy vetch and Caley pea offer winter cover and organic matter to improve soil health for summer cash crops. Warm season cover crops such as perennial peanuts and sunn hemp can be used for residual, weed, and pest management.
The climate of the delta region is similar to the Southeast but commodity focus plays an integral role in cover crop selection. As poultry operations are prominent in this region, legumes can be mixed with poultry litter and used as a type of fertilizer for row crop planting preparation to increase nutrient density and optimize crop production in spring. Vegetable growers in the Delta region can use cover crop blends to suppress weeds and mitigate soil depletion.
Cover crops in the Northeast region of the U.S. must be hardy against cold weather and tolerant to flooding. Ryegrass is a common choice as it is resilient but uses a lot of water–which can be a potential issue during times of drought. On the other hand, barley is more drought-tolerant and grows fast but does not do as well in damp soil. Both are good cover crops for erosion control.
The first thing to consider for cover crops in the Midwest is local precipitation levels. Cover crops require water, as do planted cash crops, so it’s important to choose a cover crop that requires less water with high drought tolerance. Drought-tolerant cover crops include alfalfa, red and white clovers, and more.
Cover crops in the Southern Plains are often used for both foraging and soil health management. While the coastal Southern Plains are vulnerable to hurricanes and flooding, the rest of the region is subject to extreme weather of both highs and lows. Hardy cover crops such as hairy vetch will be most resilient to a fluctuating climate.
Many parts of the West Coast region experience mild temperatures that include warm summers and cool winters. Land closer to the Pacific coast tends to experience heavier precipitation and humidity, meaning cover crops tolerant to damp soil would be better along coastal regions while drought-tolerant grass cover crop blends would benefit farms in the Pacific Northwest region.
Advocating for the Sustainable Future of American Agriculture
The initial decision to use cover crops within your ag operation takes a lot of research and a little faith but holds ample reward when implemented correctly. The benefits of cover crops can be seen within as little as one harvest season but will only grow over time. As is the case with many innovative farming practices, the first step forward is often the hardest.
As a proud supporter of American agriculture who is both financially and emotionally invested in its long-term success, AgAmerica is prepared to provide farmers and ranchers with the resources needed to create a sustainable future for their operations.
If you would like to learn more about the financing available to help you improve soil health and crop resilience in the years to come, schedule a call with one of our agricultural lending experts today.