Dry conditions have been a challenge for farmers who seeded cover crops this fall for conservation measures and spring forage.

Iowa farmers who seeded cover crops this fall may have to wait until spring before seeing their fields carpeted in green, as the lack of moisture over recent months has limited cover crop establishment and growth during and after harvest.

Morgan Jennings, field crops viability coordinator with Practical Farmers of Iowa, said because of the lack of precipitation in September and October, planting a cover crop that overwinters and has a chance to grow in the spring is likely the best bet to see conservation benefits next year.

“Cereal rye is the best species to seed in drought conditions because it’s tough,” Jennings said. “Even if it doesn’t grow much or at all in the fall, it will still take off in the spring once we’ve had some moisture over winter.

“People joke that cereal rye will even germinate on gravel or in a driveway with just a little moisture.”

Until October 30, most of Iowa was experiencing moderate to severe drought after two months of minimal precipitation statewide, according to the latest U.S. Drought Monitor. Rainfall of more than two inches that Wednesday, followed by scattered showers over the weekend and into the following week, provided a welcome boost to cover crops seeded this fall.

Nonetheless, limited emergence persists in many areas, meaning farmers may need to wait until spring for significant cover crop growth. Jennings noted that there’s still time to consider broadcasting cereal rye or drilling seed.

“Drilling is one of the most effective seeding methods in dry conditions, as the seeding method provides good seed-to-soil contact,” she said. “Another decent option at this time of the year is to simply surface broadcast some cereal rye.

“The method is relatively cheap, and you’ll still see some growth in the spring.”

Winter cereal rye can be seeded late, even into December. Once the ground is frozen, frost seeding is an option.

“The caveat is that the later you seed, the more you need to temper your expectations around fall or winter growth,” Jennings explained. “You may not see any germination or growth that fall or winter.

“After overwintering and hopefully receiving some moisture from snow and spring rain, the seed will germinate and establish, providing spring forage, erosion control, weed suppression and the benefits we like to see.”

Seeding in a dry year

Wayne Braun, a Muscatine Farm Bureau member who grows corn, soybeans, Sudan grass, and raises a cow/calf herd near Durant, noted that the dry fall delayed his cover crop seeding. Braun, who has practiced cover cropping since the early 2000s, said the recent rains were a welcome change after barely enough rain fell in October to settle the dust.

“This isn’t a new practice; my Dad and aunt had talked about when my grandpa would have a rye pasture to turn the milk cows out in the 1940s,” Braun explained. “This year I’m seeding triticale and rye as well as some tillage radishes.”

Given this year’s dry conditions, he emphasized the importance of using a no-till drill to ensure proper seed-to-soil contact and depth. “As long as there is moisture, rye will sprout just about anywhere, but in dry conditions they need the soil contact to ensure a good stand,” Braun said.

“In the spring I hope to see a lot of green. It is important for the covers to get started in the fall and winter and then go through vernalization to get a good growth in the spring.”

Rick Juchems, a Butler County Farm Bureau member, seeds 100 percent of his fields with oats, rapeseed, and winter wheat and has been planting cover crops for roughly 20 years. The dry conditions pushed his seeding back by two weeks, limiting cover crop emergence.

“Walked out the other night…, checked and saw two oat sprigs coming up,” Juchems said. “I haven’t seen anything else…, it’s been so dry. I would say with this rain we should start to see some emergence, depending on how cold it gets.”

Thad Helmig, who farms near Columbus Junction, began seeding winter wheat for a cash crop roughly 15 years ago before transitioning to other cover crop blends. This fall, they aerially-applied and drill-seeded wheat and radish on 100 percent of their fields in the third week of September. 

“We wanted to go earlier but there was little rain,” Helmig said. “Then we did get a quarter inch…, been fortunate enough to get two inches of rain, but the bulk came in just the last two days.”

Pictured above: Muscatine County Farm Bureau member Wayne Braun seeded triticale, cereal rye and tillage radish. Given this year’s dry conditions, drill-seeding helped ensure proper seed-to-soil contact and depth. PHOTO / CONRAD SCHMIDT

Multiple benefits

Braun, Juchems, and Helmig all employ multiple conservation practices on their farms to complement cover cropping, including no-till, terraces, filter strips, grassed waterways, or buffer strips. Braun is even considering installing a bioreactor for water filtration and nitrate capture.

The benefits are clear, they said, from reducing erosion and boosting soil health to enhancing water retention, weed suppression, and building organic matter.

“Taking care of the land is important,” Braun said. “I hate seeing the soil blowing across snow turning it black and gullies washed from erosion,” Braun said. “We have lost so much topsoil the last hundred years that we need to do all we can to stop it.”

Juchems added, “Soil health, water quality and retention…, cover crops make the soil more absorbent. I’ve had people walk out here when we get a rain and say the ground is actually spongy. Cover crops are kind of a no-brainer.

“It just fabulous as a weed suppressant, especially on water hemp in soybeans.”

Helmig noted that conservation practices like these also help limit nitrate runoff. “If we can start implementing these practices now, there won’t be as big of a change for us all at once,” he said.

Jennings added that many farmers see the benefit of having spring forage for their cattle.

“Not only do cover crops have the potential to feed livestock, but you can also feed your soil ‘livestock’ – the microbes that build soil health,” she said. “Cover crops are a great option for retaining moisture and reducing soil loss, and they can do so much for building soil health, breaking up compaction, scavenging nutrients.

“The potential is all there. It starts with getting the seed out.”