Pictured Above: Wallace, Neb., no-tiller Conrad Nelson says he’s been seeding a 12-way summer mix of cover crops after wheat harvest with the goal of reducing compaction, and improving water infiltration, nitrogen fixation and organic matter content. The mix includes sorghum-sudangrass, oats, rape, radish, turnip, flax, camelina, peas, soybean, lentil, clover and sorghum.]

Back in February, No-Till Farmer surveyed its readers on how they’re using cover-crop mixes to perform a variety of functions on their farms, whether it’s yield enhancement, weed suppression, erosion mitigation, building soil tilth or other benefits.

More than 100 growers responded and we printed some of the best responses in the May 2016 edition of Conservation Tillage Guide. But we didn’t have room to print them all.

So below you’ll find tips and information from another 21 no-tillers who are making cover-crop mixes work on their farm operations.

‘A Huge Shock’

In 2014 I used a mix of radish and oats after my sweet corn, mainly to keep cover on the ground to reduce wind erosion. It drives me nuts seeing brown snow in the ditches after a snowstorm.

They did the job of keeping the soil in place. The added benefit was some of the best planting conditions we’ve had last year. The ground was much more mellow than any of our other ground.

We did make a pass with our Krause Excelerator tool to incorporate our 28% and chemicals. Then we planted. The corn looked beautiful all year.

We did sidedress an additional 30 units of N. We also did check strips of no additional N. The additional N was only 3 bushels per acre better. That was a huge shock. Those acres that were covered were our highest yielding by far — on average 15-20 bushels per acre better. That sealed the deal for me.

This past year I planted a mix of radishes, oats and cereal rye on our sweet corn ground. It was harvested earlier than last year, allowing for more growth than last year. Radishes grew to about a foot above ground and the size of a forearm. Oats were knee high and had great growth on the cereal rye.

Where we’re planting soybeans this year, we’re going to no-till into the covers and then terminate them. We do have 45 acres going to corn where covers will be terminated early, plus worked by the vertical-tillage tool to incorporate N, plus a sidedress application of N.

— Carl Zimmerman, Earlville, Ill.

Challenging Conditions

No-till is not a common practice here, so we’re still learning by trial and error to see what works for our conditions.

After suffering from severe compaction, we decided to deep till our fields this year. Our goal is to plant a three-way winter cover crop of either oats/rye/triticale, plus either field peas/vetch and radish, to build organic matter and cover to see if this will prevent compaction in the future. As an early adopter of no-till we didn’t know back then what we know now about managing your soil cover.

We’re in a summer rainfall region with very cold winters and little or no rainfall or snow in winter. Cover crops have to be planted with residual summer moisture. Cover crops have to be frost resistant and survive with little moisture, so options are limited. Mixes also depend largely on seed availability.

— Ruhan Theunissen, South Africa

Building Up Biomass

We planted several different mixes last year. One mix was spring oats (2 bushels an acre), radish (4 pounds) and sunnhemp (15 pounds), which was drilled into wheat stubble Aug. 25, 2014.

My goal was to test my theory that oats, radish and sunnhemp would provide enough biomass to make a suitable mulch for no-till corn in 2016 that would not require a burndown herbicide. All those species will winterkill.

Another mix was Austrian winter peas (25 pounds), radish (3 pounds) and sunnhemp (15 pounds) drilled into wheat stubble Aug. 14, 2014. I’ve planted this mix before, with nice results for no-till corn as the next crop. This has two legumes — one warm season, one cool season — plus the soil loosening by the radish. I’m trying to use the long fallow season to capture as much N as possible.

Another mix was wheat (2.5 bushels) and Austrian winter peas (20 pounds) drilled into soybean stubble on Oct. 17, 2015. This is planted in a rotation with other fields close to the main farm (formerly dairy) with the intention of harvesting as silage hay prior to no-till corn. These fields are high in phosphorus (P) due to the decades of dairy manure application, and this double-crop nutrient removal is helping reduce excessive P levels.

I soil test every year so I can keep up on soil conditions, and I’m adding compost to replace organic matter and potash when needed. I’ve also done a test plot within this field by replacing the peas with Balansa clover. It’s advertised to have much more biomass than the peas in the same season, while still being very winter hardy and fixing N. The cost per acre for the seed is much less as well.

— Lyle Tabb IV, Kearneysville, W.V.

Filling the Gaps

Following no-till spring wheat that was interplanted into red clover and harvested for grain, we had drainage tiling work done. We did very limited tillage work directly over the tile lines and whole-field no-till planted a seven-way mix of canola, lentils, forage radish, turnips, sudangrass, and flax.

The primary goal was to get biological activity going in the heavily disturbed soils. Secondary goals were weed suppression, forage for cattle, drainage and snow catch. Due to the excellent growing conditions and extremely late frost we had fantastic growth, a lot of forage for cattle, and excellent snow catch. 

The interplanted red clover dominated the mix, but because of a variable stand of red clover from interplanting, the cover-crop mix filled in all the gaps and ensured 100% coverage.

I’m looking to try vetch and cereal rye instead of just cereal rye following silage corn and soybeans like I’ve been doing for a couple of years. Following spring wheat I will again use a multi-species mix, but will likely eliminate sudangrass and flax and instead add sunflowers and perhaps a bean or pea.

— Paul Ortman, Marion, S.D.

A blend of radishes, Austrian winter peas, barley, crimson clover, buckwheat and Sunnhemp seeded after corn harvest last August. The corn only yielded about 40 bushels due to the extreme dry weather, so the covers soaked up all the excess nutrients and grew well, says Mount Ulla, N.C., no-tiller Brian Moore.

Doing What Works

In the fall of 2015 our cover acres were down mainly due to wet weather, and our wheat acreage was up. The acres we did seed were behind corn. We seeded radish, peas, barley, clover, buckwheat and sunnhemp on several fields.

Several other farms just had wheat and clover on them. This fall we hope to use rye, clover buckwheat, radish, peas and barley.

Our main reason for not using more cereal rye is that we don’t want to get our seed wheat and seed barley contaminated, although I think rye is a better cover than wheat and barley.

— Brian Moore, Mount Ulla, N.C.

One of Each

After wheat, I seeded an eight-way mix with sunnhemp, buckwheat, sunflowers, cahaba vetch, radishes, rape, turnips and millet. I wanted to grow organic matter and nitrogen and improve soil health.

After corn and soybeans I used annual ryegrass, crimson clover, rape and oats. This was to fix or sequester nitrogen (N), feed soil microbes, stop erosion, loosen the soil and mulch for next year. I feel like I get all of these benefits. This year I will experiment with different cocktail mixes after wheat but stick with the same mix after corn and soybeans.  

In choosing mixes I look at what I want to do and what works best, and when I will be seeding it. Also, I look at how the different species work together. At the minimum I want a grass, a legume and a brassica.

— Roger Wenning, Greensburg, Ind.

Greensburg, Ind., no-tiller Roger Wenning shows a field with aerial-seeded annual ryegrass, crimson clover and rape right after corn harvest last fall.

Moving Forward Carefully

We farm in western Kentucky near Paducah area. Two years ago, due to the collapse of the wheat market, we started planting straight cereal rye on our sloping ground that didn’t have a wheat crop on them.

Our only goal was erosion control and it worked very well in that role. We also had far less Palmer amaranth pressure than many of our neighbors.

Last fall we mostly planted cereal rye and tillage radishes behind our corn and switched to straight rye as we moved into October. Cereal rye was for erosion control and radish for bio tillage. We used a low rate of radish — the ratio was 50 pounds per ton of rye, and the seeding rate came out to 42 pounds per acre. We even planted some cereal rye behind double crop soybeans with excellent results due to the very mild December.

On a few fields we’ve set up trials and planted a multi cover-crop blend. On one I planted cereal rye, radish, rape, Berseem clover and Lynx winter pea on Sept. 19. I chose Lynx pea due to cold tolerance, the Berseem clover was a mistake by my supplier (I ordered crimson) and planted it before I realized it.

I chose both radish and rape to have two types of taproots and one to overwinter, as well as for cost reasons. Rape was $1 per pound and a very low rate was required. As of February this year, it appeared all but the radish and Berseem clover overwintered, but Berseem doesn't seem to fit in our production systems.

The cereal rye has held very well for erosion in all fields and the radish had pushed very deep. In the above five-way mix, the radish grew a lot with the mild winter and they followed corn behind spring-killed alfalfa. It looked like they could reach the deeper alfalfa roots for an N source. 

In an additional field that was seeded Oct. 6, 2015, I planted cereal rye, purple-top turnip and a forage-type radish. I wanted to see how the turnip overwintered vs. the radish. Planting was later than ideal for either but it was 70 F when I planted that field. I also chose turnips with cereal rye as an anti-Palmer amaranth mix. Some turnips made it to early February if they were protected by larger rye.

I plan to do more cover mixes, but planting dates don't warrant it. As a mid-South grower we easily can plant double-crop soybeans behind wheat, and the cereal rye we keep for seed, so many of the cover blends behind wheat don't work for us. I intend to keep experimenting, as I’m very new to this process.

We select cover-crop mixes primarily on goal. Last season we mostly had a two-plant mix and a experiments with five-ways. The best research I’ve seen says there’s a rapid increase in benefits with three types of plants, not just the species difference but having different plant types — a brassica, cereal and  legume. So if we can find fits we may add plants.

Our primary concern is erosion control, so we’ve gravitated to cereal rye due to its flexibility, and we can raise it ourselves. My father and uncles even bought an old seed cleaner to clean their seed, as it’s hard to get it cleaned in this area.

I may try some annual ryegrass for fragipan breakup based on some interesting work from Dixon Springs, Ill., and Lloyd Murdock at the University of Kentucky’s Princeton experiment station. We used radish with the intention of bio tillage and adding a different type of plant, a brassica. 

I’m trying some legumes to try to increase biomass in some fields and provide enough N to help offset some to the tie-up issues from residue. Our cropping patterns and planting windows don't leave a lot of room to have much legume N fixation, anyway, so that isn't a priority.

— Derek Martin, Paducah, Ky.

Various Application Methods

We like to use a mix of annual ryegrass and rape in soybeans, sown with a rebuilt Gandy seeder on an Apache sprayer. We strip-tilled dry fertilizer after harvest with a three-tank variable-rate program, including micronutrients, for the 2017 corn crop.

Cereal rye was seeded with an air drill after corn harvest for 2017 soybeans. In 30 acres of corn and soybean fields we didn’t get replanted. We air drilled cowpeas, sunnhemp, Cahaba vetch, yellow sweet clover, crimson clover, oats, sorghum-sudangrass, pearl millet, radish, rapeseed, turnips, buckwheat, sunflower, flax and added leftover soybean seed.

We were concerned about herbicide carryover but got a great stand in the replanted soybeans and a good stand in the corn. We believe the excess rain removed the herbicide carryover. The known benefits are water infiltration and weed suppression. 

We’ll continue to seed annual ryegrass and rapeseed in soybeans and cereal rye after corn. We will test interseeding annual ryegrass and crimson clover on 100 acres of corn this year. We plan to sow covers into standing corn with our Gandy and immediately follow with sidedressed anhydrous ammonia to stir some dirt around the seed.

Potential herbicide carryover, growing season remaining and seeding methods are among the factors when choosing cover mixes. We didn’t think we were getting enough benefits from turnips or crimson Clover.

— John Busby, Frankton, Ind.

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