Lessons Learned

A farmer examines the root structure of rye grass. Cover crops play an important role in the Iowa Nutrient Reduction Strategy.

Farmers Share Lessons Learned at Cover Crops Boot Camp

BY ZITA QUADE

Discussing cover crop success, while debating the challenges, was among the exercises undertaken by more than 100 farmers and industry leaders who gathered in Ames for a Cover Crops Boot Camp.

The recent event was led by Sarah Carlson, Practical Farmers of Iowa, with extensive planning input from members of the Conservation Infrastructure Cover Crops Working Group and several partners, including the Iowa Soybean Association and the Iowa Agriculture Water Alliance.

Two succinct farmers’ comments summed up much of the wisdom shared:

“If you want to succeed at cover crops, you will,” notes one attendee. “If you want to fail at cover crops, you will.” Another attendee says, “Don’t be afraid to be different, be afraid to be the same.”

Iowa farmers know cover crops play an important role in the Iowa Nutrient Reduction Strategy to improve soil health and improve water quality. To examine the latest cover crop science and practices being implemented, a variety of experiences were shared by farmers and specialists in soils, livestock, equipment and fertility.

Presenters shared these overall lessons learned:

• Cover crops require patience and adaptability, as numerous variables are at play and every season and field is different. Start small and incrementally work cover crops into an operation. Planting cereal rye ahead of soybeans is a good place to start.

• Over time, a no-till or strip-till system with cover crops will lead to more forgiving and fertile soils.

• Cover crops help weatherproof the farm (e.g., increase water retention, hold soils in place and increase resilience).

• Cover crops improve soil health by improving soil aggregate stability, increasing soil carbon and organic matter, providing living roots in the soil prior to row crops establishment in the spring and post-harvest in the fall when Iowa receives the most precipitation, and soils are most vulnerable to nitrate loss and erosion. They reduce compaction, improve porosity and infiltration rates, and serve as a food source for soil microbes, earthworms and other soil invertebrates.

• Cattle feed costs can be reduced in the fall by grazing cover crops. Manure can reduce fertilizer input costs.

South-central Iowa farmer Mike Jackson teamed with Iowa State UniversityExtension cropping systems specialist Mark Licht to discuss four keys tosuccess with cover crops. Key takeaways included:

1: Mindset

• Cover crops call for a shift in mindset. Don’t give up on the first stumble; it takes effort to make things work.

• Determine goals and set expectations – Looking for cover crop biomass for weed suppression? Feed value for grazing? Improved soil health? Jackson wants erosion control and nutrient stabilization. Last spring near Oskaloosa, he had 10 inches of rain in 10 days, and without cover crops, “the soil would have been halfway to New Orleans by now.”

• Find a farmer-mentor with similar goals to talk to about this new system. Also, find and join some cover crop Facebook groups, alongside researching and reading.

• Document actions to help plan effectively and make informed decisions for future management.

• Jackson’s long-term goal is to leave his sixth-generation farm to his son, Mack, with better soils and a strong commitment to continued land improvement.

2: Equipment Setup - How to deal with cover crop residue in the spring

• Licht says farmers need to pay additional attention to planter settings to succeed. This includes a sharper focus on toolbar down-pressure on the row-unit, seeding depth, and closing the seed furrow.

• Jackson says that since they don’t strip-till, they keep planter components sharp and up to date. They use spiked closing wheels, working about two inches of the soil — all that’s needed when following cover crops.

• Get off the tractor and check your planting depth. If there’s an inch of biomass on top of the soil, set the planter deeper.

3: Fertilizer

• Licht recommends putting nitrogen (N) on in the spring, and when the crop actually needs it. Optimally, total N needs are the same if there is a cover crop or not, it’s just rethinking N timing. You don’t want fall applications taken up by cover crops.

• Jackson applies a lot of hog manure and uses a shallow vertical-tillage tool to incorporate it. His second trip in a field is with the corn planter and he puts 5-6 lbs. N in-furrow. The third trip is with a sprayer to burndown the cereal rye cover crop. He adds 5 lbs. N to help break the rye down. Total N is about 180 lbs.to achieve a 200 to 220 bu. corn yield average.

• To ensure it’s not being overapplied, tissue and soil sampling, as well as some post-harvest stalk nitrate sampling, is conducted.

4: Seeding Methods

• Aerial and broadcast seeding allow for earlier application and more acres can be covered faster. The downside is a less uniform stand and poor establishment under dry conditions.

• Seeding with a high clearance interseeder usually delivers more biomass due to earlier seeding, allowing more time for heat units to accumulate.

To learn more, visit IowaCI.org. Contact Zita Quade at zquade@iowaagwateralliance.com.