Farming Smarter with Cover Crops

Editor’s note: reposted with permission from The Farmer’s Life.
Last September we seeded our first round of cover crops on roughly 200 acres. These crops that we will never harvest are probably the most exciting thing on the farm right now for me.

What is a Cover Crop

A cover crop does just what it says. It covers the soil during the period between the time you harvest one crop and plant the next.  For my farm this means winter. Our cover was seeded by airplane in mid September just ahead of harvest.  We chose aerial application in order to give the seeds a chance to start growing before harvest and before winter set in. Next year I think we need to be seeding in early September to see more growth ahead of cold temperatures. Flying seed on requires more seed to account for seeds that won’t germinate as well compared to using a drill or planter to place the seed in the soil, but a plane allows you to get started growing before harvest.

Cover crops provide erosion control, improve soil structure, increase organic matter, scavenge soil nutrients, suppress weeds and pests, and some can be used as forage for livestock. But not all cover crops accomplish all these goals. Each one has its own unique qualities and must be managed differently. Many of them work even better when they are planted together on the same ground.

My Cover Crops

Ryegrass looking good. I think we can get a thicker stand by seeding earlier next time. However, I have learned that with cover crops the activity below the ground is more important then the greenery you see on top. Our ryegrass came directly from a grass farming friend in Oregon.

For now I’m just going to talk about the cover crops we have on our farm right now. First we have annual ryegrass. Ryegrass can develop very deep roots quickly. I attended a cover crop field day and saw ryegrass roots less than two months old that were already over 3′ deep in the soil profile. That’s amazing. Those roots are pulling up nutrients and when the grass dies those root channels will improve water infiltration and leave paths for next year’s crop roots to follow. Beneficial organisms like earthworms will follow those paths as well. All this while building soil organic matter and structure.
Getting rid of annual ryegrass is probably the most important part of management. The grass needs to be sprayed in the spring when it is actively growing.  That means you have to wait until temperatures begin to warm up. If the grass isn’t growing it won’t take up any herbicide. If spring is warm and wet ryegrass can get tricky. Wet means you can’t get out in the field to spray giving the ryegrass time to grow even more and become tough to kill. I don’t foresee this being a huge problem, but important to know about ahead of time.
Adjacent to the ryegrass we are growing winter cereal rye. Cereal rye may not grow as thick or have as much of a root system as ryegrass, but it has some great qualities of its own. Allelopathy is one of those qualities. Cereal rye has the natural ability to suppress weeds. I also learned during the field day that cereal rye may have an effect on soybean cyst nematodes as well. The agronomist on hand all but guaranteed a 4-5 bushel bump in soybean yield if you have nematode problem. Lower pesticide use makes everyone happy right? Unlike ryegrass, you can plant into a growing rye cover crop and kill off the rye after planting. If we go that route, I’ll have some pretty neat pictures of the planter rolling through a green field of fairly tall rye. That’ll be kinda weird. It may be taken care of with the grass though since they are in the same field.
Oats and radishes.
Oats and radishes.

Finally we have about 120 acres of a mixed cover growing in one field. Oats and radishes growing together. These two crops will winterkill when the temperature stays around 20 for a few days. Ours have already died off in the last two weeks.
Radishes are really cool because they send a big tap root deep into the soil along with fine-haired roots. They are great at soaking up nutrients that may otherwise be lost to the atmosphere or through groundwater. When spring comes and the radishes start to decay they will slowly release those nutrients to the corn we will have planted by then. I should note these aren’t the radishes you are used to eating. These are called tillage or groundhog radishes.  They are white and look somewhat like large carrots.
Oats are great because they scavenge nitrogen. Nitrogen is very important to a corn crop. Oats develop deep roots to improve soil structure much like ryegrass. I hope our oats/radish mix really show some results in next year’s corn.

Favorite Things

Picking up cover crop knowledge at a field day. That is a huge radish he is holding. This pit is in a bit of an experimental field. The farmer had a failed crop due to the drought so he planted radishes and ryegrass in July. This shot was taken the first week of November.
Picking up cover crop knowledge at a field day. That is a huge radish he is holding. This pit is in a bit of an experimental field. The farmer had a failed crop due to the drought so he planted radishes and ryegrass in July. This shot was taken the first week of November.

What excites me most about cover crops is keeping more of what we have and potentially using less inputs in the future. I feel that increasing organic matter alone will be a great improvement to our farm even without all the other benefits. As organic matter increases soils can handle water better and hold on to and provide more nutrients to a growing cash crop. Improved soil structure means our crops will grow deeper roots.  Having an active root system in the ground twelve months of the year instead of six means the beneficial organisms in the soil will be more active which is really good.
Nitrogen is one of our most expensive and most necessary inputs.  If cover crops can allow us to either use less nitrogen or at least do a better job of effectively using the nitrogen we apply that will be a huge bonus for corn. Boosting yields on one end and cutting costs on the other end is a pretty great combination. Cover crops aren’t free, but I think their benefits will far exceed the costs.
Cover crops can also break up soil compaction.  Compaction caused by driving heavy equipment over soil limits water infiltration and root growth.  This is a reason no till and cover crops go so well together.  In a true no till situation you won’t be doing any deep tillage to deal with compaction, and cover crops give you a way to deal with that.
When spring comes around you’ll definitely being seeing more about our cover crops.  I’m sure we’ll be seeding more this fall too, and maybe we’ll try a few different things.  If you’d like to learn more about covers crops check out Plant Cover Crops.  Dave runs a great website over there and just so happens to be pretty close to our farm, making his data that much more relevant to me.
Brian farms with his father and grandfather on 2,300 acres of land in northwest Indiana. They grow corn, soybeans, popcorn, and wheat. Brian blogs at The Farmer’s Life.


  1. I just love this post – thank you for taking us along on your learning process as you test different cover crops to see what is best for your farm. I think people associate things like cover crops with only organic farming, but it’s important to show that “conventional” farmers use many sustainable methods, trying to reduce their overall environmental impact, boost soil organic matter, and reduce the need for pesticides on their farm. It just make sense – even if it costs you a little more for the cover crop seed, you are going to see short term cost benefits if you need less herbicide the next year, and long term cost benefits as your soil is improved and erosion is reduced. Please keep us posted on your successes and lessons learned as you more forward!
    Quick question – do you know if Dave from Plant Cover Crops is on Twitter? I’d love to keep up with his posts, but with so much media overload, I don’t really use an RSS feed reader anymore. It’d be great to keep up with his posts (like I already do with yours) on Twitter (or Facebook, or G+).

  2. Thanks for resposting! Dave is @plantcovercrops.
    I think only 1% of Midwestern farms are using cover crops. If they prove to be an advantage, then I feel like I’m ahead of the curve which is a good place to be. I’ve already heard that seed may be difficult to come by this year as cover crops gain popularity.

  3. Glad they are becoming more popular. I wonder why more farmers weren’t already using them. Perhaps the benefits of cover crops just wasn’t known among the community of farmers with larger farms? Based on what I learned in my sustainable ag classes, cover crops have been used for a long time on smaller farmer, organic certified, etc.

  4. I do have the thought of “Why weren’t we already doing that?” I don’t think it’s that farmers don’t know of the benefits because I believe they were a common practice at one time. Of course most everybody had crops and livestock at one time as well, which would make a difference.
    Cost would be an issue as well. I think some believe they won’t pay without subsidies. Personally I don’t think cover crops should be subsidized at all. To me they are another input like fertilizer. But sometimes we need incentive to get the ball rolling. Also I don’t think people try stuff long enough. I’m actually not holding my breath on seeing great results this year. I’ve told Dad even if we don’t expand acres I want to keep the two fields we have now in a cover crop rotation for 3-5 years. Same with no till. One year doesn’t tell you much.
    Note of interest to you. We know farmers sometimes have trouble dealing with corn residue especially in corn on corn. At the field day I went to the agronomist said he has some guys who have been no tilling and cover cropping for 5-6 years now and they are complaining they don’t have enough residue because it’s degrading so fast now.

  5. I bet the improved soil organic matter means more “good” bacteria which decompose the residue faster. Very cool and a sign of healthy soil. Good reason to do cover crops, to keep feeding that soil. What about clover as a cover crop – it’s a nitrogen fixer, right? Could be a good companion corn if you’re not planting beans.

  6. I work in the Mid-Atlantic region where I think we’re far ahead of the cover crop curve ball. The last NRCS data that was released said that of the Chesapeake bay watershed 4% of crop ground was under cover crops. That data was from 2003 to 2006 and includes areas of northern PA and southern NY where climate drastically limits the utility of cover crops.
    That number is meaningfully higher today and in areas closer to the bay where nutrient loading is more detrimental to water quality. I estimate (that is to say a wild windshield survey!) cover crops are used on probably 30-40% of our silage corn acres and probably 10% of grain corn acres. It goes up every year. MD and DE have subsidized the cost of cover crop establishment in the $30-40 per acre range which more or less pays for the practice. Many of my large grain growers on the Delmarva are very big into the idea for agronomic, environmental, and economic reasons.
    I live in PA where there is no cost share program, but the practice is still widely practiced because we know the benefits that Brian talks about. We also benefit from a significant amount of dairy farms which means we can take corn for silage off much earlier than grain. This makes establishment MUCH easier, and we can utilize the cover crop for livestock forage. As one of my large PA dairy customer puts it, “I work all year so why shouldn’t my crop acres?!” Here, we have both large and small growers utilizing the practice. Adaptation is more a function of progressiveness and long term outlook.
    I will say however that cover crop adaptation has hugely benefited from a positive ag economy and cost share. $35 dollars an acre is not a trivial cost. It will be hard to justify with $4 corn. That said, I’m a HUGE fan of the practice. We’re already turned no-till from an alternative practice into the majority. As of 2012, 54% of PA corn and soybean acres are no-tilled. That’s huge…and I can see cover crops following close behind. Both no-till and, to a somewhat smaller degree, cover crops are much more easy to manage with the flexibility offered by herbicide tolerant crops.
    Enough bragging about my farmers! And thanks again Brian for what you share.

  7. There are a lot of nitrogen fixers being used as cover. Crimson clover, cow peas, and hairy vetch I believe. From what I understand cover crop cocktails often have a synergistic effect and manure just takes it all to another level.

  8. You mentioned subsidies. Is the cost that substantial? For example, it looks like a lot of people fly on the seed for logistical reason. Is that a pricey thing to do?

  9. I honestly don’t remember what we paid for everything off the top of my head. I know the ryegrass was $.70/lb which is pretty cheap in my opinion. That doesn’t include application.

  10. I do know NRCS was sending out flyers to encourage people to plant cover crops to capture nutrients not used because of the drought in hopes of preventing leaching.

  11. So possibly a subsidy could be aimed to cover short term economic loss in hopes of long term soil improvement. Not suggesting it is best for Wyo or Neb, etc, just trying to get a better feel for the subject here. The promotions say (vids on TouYube) long term soil improvement should lead to better moisture retention, which would seem to be a desirable outcome in dryer areas. If true, the trouble would lie in reaching the long term economically.

  12. Yep. The issue is we don’t know how long it will take (if ever) to reach that point where the investment actually makes water retention increase. There is a group of University researchers looking at that very thing, but it will be years before we really know the answer. So it’s tough to create policy when we don’t know if it is a sustainable practice. But there are proven benefits in areas that are not moisture limited.

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