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Serving: IA

Got ya covered: How cover crops benefit Iowa farmer

Cover crops provide benefits for farmers; they build soil quality and provide forage for cattle, but they can also help improve yields and lower feed costs.

Thirty-five years ago, Justin Robbins’ dad gave him a heifer. He was 8 years old. And if ever the saying were true — that farming gets in your blood, and you know it’s what you’ll do — it’s been true for Robbins. After that heifer, he went to work for a neighboring farmer. He learned to care for the land, and it has become what he knows, what he enjoys and what he does well.

Through the years, Robbins and his wife, Lacie, have grown their beef herd and their crop acres, and they’ve added practices to help ensure they can pass down the farm to their son, McKinley. In 2013, they started planting cover crops to help improve soil health and provide forage for their cow herd. Since then, the use of cover crops has also decreased feed costs and helped increase yields on their Scranton, Iowa, farm.

Cover crop specifics

Mark Licht, Iowa State University Extension cropping systems specialist, says farmers have a lot of cover crop options, but the most common in Iowa are cereal rye, oats and radishes. Others include hairy vetch, red clover, cowpea, rapeseed, winter wheat, triticale and annual ryegrass.

“Finding the right cover crop for your farm depends on your goals, [and] how and when you are going to plant, and your corn and soybean management practices,” Licht says.

Robbins has tried different seed mixes on his farm, but most recently uses cereal rye, oats and radishes for his cover crops. “What is most important to realize with cover crops is, you have to adapt to the conditions each year and realize no two years are the same,” he says.

Benefits outweigh challenges, Robbins adds. He’s measured more organic matter in the soil. He can see more good insects such as earthworms by simply moving some of the ground cover in an unplanted spring field.

Licht says the biomass production from cover crops will increase soil health, reduce soil erosion and provide nutrient loss reduction benefits. Winter and spring small-grain species provide more biomass on corn and soybean fields. In seed corn and corn silage fields, farmers could try legumes like hairy vetch and red clover, or brassicas such as radishes and turnips. The increased biomass can also alleviate soil compaction or nitrogen fixation, according to Licht.

Being flexible

Before you add cover crops and work through those new conditions, know your ground and what it needs — and how to get cover seed planted.  

Early on, Robbins seeded with a high-clearance bean buggy that he retrofitted with an air seeder unit. Since then, he has found more effective sources for seeding. He prefers either drilling the seed or blowing the seed on with an altered high-clearance sprayer with airbox attached, but the seed can be applied by airplane on wet years — and he always keeps that as a backup plan.

“It really depends on the situation. The drill works really good, but it’s a lot smaller window to use that method,” Robbins says. “It’s also important to use a method to get the proper seeding rate. I like 1 bushel of seed per acre; otherwise the stand gets too thick, and the plants are competing with each other too much.”

Other benefits of cover crops

Besides building soil health, reducing soil erosion, supporting earthworms and suppressing weeds, cover crops provide good forage for Robbins’ cow herd.

“We always graze cornstalks in the fall — this year from mid-October through January — and the cover crops add nutrition for our cows,” he says. “Some fields you will see very little cornstalk residue. The cows love to graze through the winter, and it reduces the amount of stored feed needed.”

Robbins has both baled and chopped the rye in the spring prior to planting. Cover crop harvest all depends on timing. If the rye is cut and sets in the field too long, he will bale it, but if the chopper can come soon after it is cut, it will be added to a pile where it is ensiled for at least two weeks and then fed.

Between $12 and $15 an acre is spent on cover crop seed, but by allowing each cow to graze these acres and harvesting forage off these fields, Robbins says he saves more than $1.63 per head in feed costs.


Iowa State research is continual regarding cover crops in several areas of the state. “Cereal rye germinates and grows quickly in cooler conditions, and will survive the Iowa winters,” says Alison Robertson, Iowa State University Extension field pathologist. “Rye and corn are similar plants, and the rye can harbor some of the same pathogens and pests as corn. Therefore, we must continue to study these cover crops and make sure the benefits outweigh the challenges.”

Robbins says the only challenges he’s seen is a small amount of yield drag in some fields where cover crops have been planted, but he hasn’t nailed down the reasoning — as most years he can see an increase in yields. He’s also learned to spray anhydrous in the fall, as an agronomist informed him spring application can kill earthworms, which he absolutely doesn’t want to do.

“Farmers may try cover crops and have a bad experience and then not want to try them again. But if they have a good experience, they will likely increase the number of acres where cover crops are planted,” Robertson says.

Robbins will continue to increase use cover crops on his farm because of the benefits. His attention to these conservation and stewardship practices will help his farm be productive for many generations to come. It has also helped the Robbins family win the 2021 Iowa Environmental Stewardship Award through the Iowa Cattlemen’s Association, and then be awarded the Region III Environmental Stewardship Award through the National Cattlemen’s Beef Association.

TAGS: Conservation
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