Q: What advice do you have for closing the seed slot in heavy clay soils? I've tried many systems, and closing the seed slot in heavy clay soils. I farm in Michigan, only 1 county up from Ohio. 

— Phillip Gordon, Saline, Mich.

What kind of planter are you using? Also, fixing closing issues starts at the seed opener. We started with Kinze, went to Case and now have a Horsch. Each one responds differently. The Kinze was not strong enough for our tough soils. We really liked the Case but had to switch the OEM RID (reduced inside diameter) gauge wheels for a Deere style because the RID allowed the sidewall to blow out and not close properly.

We also took the small convex disc closers off and replaced them with a fingerstyle. Then we took the wide 4-inch firming wheel off and replaced that with a V-style closer, an Xtreme Furrow Cruiser from Copperhead Ag. We next discovered that our Case could not give us consistent depth.

We plant green, and if our cover (hairy vetch, crimson clover and turnip) is robust, then the top 1/2 inch doesn't want to close too many roots. But if we push the seed to 2 1/2 inches, then the bottom 2 inches is crumbled and closed nicely, so we went looking for a planter that would get us there. That brought us to a Horsch. We kept the Xtreme Furrow Cruisers off our Case and have those on our Horsch.

However, we can still mess up with a Horsch. Plenty of other planters do a good job. I had to look at my planter unit as multiple jobs in one pass. Opening discs, depth, etc. Analyze it all and figure out why it won't close. You may just need different closing wheels.

— Larry Dyck, Campden, Ont.

I agree with Larry. Get a Horsch. It’s an amazing planter for us planting corn into green covers. Our soils vary from too-soft prairie soils to hard tight clays on every pass across the field, but the Horsch manages it all. Call Ty Brown if you want to learn more about it.

— Ken Rulon, Arcadia, Ind.

We are in western Pennsylvania in the glacial moraine. Soils can change 3 or more times in 100 yards! We’ve had good luck closing with the Yetter Copperhead wheels on our John Deere 1755 set at about mid-pressure in the closers. It’s not always perfect, but we’ve thankfully had good stands with this setup. Good luck to you!

— John Beatty, Butler, Pa.

We really liked the Schaffert Zipper closing wheels we ran last spring. They have several models. and I'd talk to them about which ones work best in your area. They do well here in the local-ish Beck's PFR. We actually selected them for a high-speed planter as the angle of the teeth throws less soil. But they seem to have great slot-closing ability at moderate pressures.

They have several weights of closers as well based on how thick the cast wall is or a mud smith-style wheel. What I like about them is the teeth seem to smash the sidewall and make the dirt loose enough to close well. One thing I learned running hydraulic downforce planters over the last several years is speed makes everything harder to do, even if our ground is softer than yours. Those seem to have good operating margins.

 — Derek Martin, Fancy Farm, Ky.

It saddens me to read how so many of you are still having to focus on trying to improve the performance of your no-till corn planters. I am now 82 years old, but as a 25-year-old scientist and agricultural engineer, I could see precisely the same issues appearing as you are directly reporting some 67 years later. What this says to me is that the machinery manufacturers have still not learned how to make fail-safe corn planters.

I was commissioned to write a book on this precise topic by the Food and Agriculture Organization (FAO) of the United Nations in 2006. There are chapters in this book that address your specific issues.

The book (No-Tillage Seeding in Conservation Agriculture) resulted from a huge amount of research that my team did on the subject of no-tillage opener designs when I was a scientist and agricultural engineer at New Zealand’s Massey University. The three most important principles relating to your problems corn planter problems are:

1. The single worst shape of no-tillage slots that you can make (measured in terms of their measured biological failure rates) are vertical V-shaped slots.

2. The larger the seed, the more demanding it is of needing to be placed in exactly the right soil micro-environment (slot) during no-tillage — and there are few seeds larger than corn.

3. But almost every brand of no-tillage corn planter in existence uses double disc openers that make V-shaped slots (the worst possible combination).

4. No wonder everyone is still having problems with no-tilled corn.

What you currently have is a choice of planters that are all equipped with the worst possible openers (double disc) for sowing large seeds like corn.

I have attached copies of a small number of chapters of our book on this topic because all copies of the book were sold out soon after it was released in 2006. Part of the stimulus for writing it was generated by the US Senate which had heard about the unique research we were doing in New Zealand and asked me to address a special hearing of a sub-committee of the Senate in 1989. They asked us to explain what US machinery manufacturers were doing wrong for no-tilled corn, even at that time.

Do you know that not one single no-till corn planter manufacturer (anywhere in the world) took the slightest notice of what I had to say to the US in 1989? This is why you are still struggling to find a fail-safe way of no-tilling corn 34 years later in 2023.

I am happy to discuss the topic with anyone who cares to contact me and can tell you that there is now “light at the end of the tunnel” regarding the design of no-tillage corn planters in the US.

 — John Baker, Feilding, New Zealand

The Cros Slot opener is one that has intrigued me. I recall innovators in my area working with it 35-40 years ago, and yet it has never taken hold. Before we made our last planter purchase, we did some investigation. There is an outfit a couple of hours from where I am with one, and I have chatted with them. They are on a much nicer soil than mine. There were things about their Cross Slot that they liked, but a number of things they didn't.

I don't recall all of that conversation. One question I had, does the seedling come up vertically from the "shelf" where it is sitting, or does it have to flex over to find the vertical slot? I glanced through the chapters you attached. Maybe I am misunderstanding. I am presuming the inverted T is a cross slot where the seed is placed on a "shelf" created by a boot and then the soil I pressed down. The concept makes sense and yet in our varied soils, it hasn't fully taken hold. Yes, the manufacturers are partially to blame, but we as growers also have to express a desire.

— Larry Dyck, Campden, Ont.

I agree that in a no-till environment, one of the issues in closing the slot is the double disk openers. That is why I only use the prescription STP double disk openers on both of my corn and soybean planters because it does not make the V-shaped slot as a common double disk opener does. I plant into a green cover, and ever since I started using these, along with having the Dawn Gaged Tine closing wheels, I have had great success with closing the slot.

I also feel that another benefit is planting deeper to offset soil conditions that are not conducive to planting, especially in heavy clay soils. I plant my corn 3 inches deep and my soybeans 2 inches deep. Even emergence is more critical than having a delay in emergence, so therefore planting deeper helps offset different soil conditions. Also, sometimes we get a little impatient and want to push the envelope at our planting window with planting too wet and that adds problems in closing the slot. Lastly, in a no-till and cover crop environment, after a few years, our soils are much more mellow than in a conventional till system so closing the slot by making a few changes should not be an issue. Patience pays!

— Mike Starkey, Brownsburg, Ind.