Turning Dirt! Part Six: Cultipackers

By Mark Trudeau, National Sales Manager

In the last few Turning Dirt articles we have discussed how to select and properly use seedbed finishing equipment.  In this article, I’ll complete that discussion by revisiting in greater detail an optimum implement for preparing seedbeds for small seeds: cultipackers.  

To understand the information in this article, you’ll need to have a good grasp of the information I covered in Turning Dirt, Parts 3, 4 and 5, so I urge you to review those articles before reading this one.  All previous articles in the Turning Dirt series are available in past issues of Whitetail News, and on-line at  http://www.whitetailinstitute.com/info/news/.
Cultipackers: Definition and Optimum Size

What is a cultipacker?  A cultipacker is an implement used to smooth, firm and eliminate cracks from a seedbed that has been disked or tilled.  Its main components is a packing-cylinder assembly, which consists of a row of wheel-shaped “packer plates” mounted side-by-side on an axle.  The outer edge of each packing plate is peaked, giving the packing cylinder a wavy, or “corrugated” packing surface when the plates are mounted side-by-side on the axle.  The peak of each packing plate is either smooth or notched.   The packing cylinder is mounted to a frame by bearings, which allow the cultipacker to roll as it is pulled across the ground.

Cultipackers come in a wide variety of lengths, weights, sizes and configurations.   The smallest cultipackers have only one packing cylinder, while the largest may have multiple cylinders.  Also, some are stand-alone implements, and others are included as cultipacking components of a variety of multi-task implements.  (One of the most familiar multi-task implements to most hunters are food-plot planters that have a seeder, disks and harrows with a cultipacker mounted in the back.)

Food-Plot Cultipackers – Optimum Features.  In this article, we’ll keep it simple and just talk about stand-alone cultipackers.  The most versatile and efficient stand-alone cultipackers for most food plotters will have the following characteristics:
(A)  A total length of 3 feet to 12 feet
(B)  A single packing cylinder
(C)  Packing plates with a diameter of about 8 inches to one foot
For simplicity, I’ll refer to these as “FPCs” (food-plot cultipackers).  For comparison, I’ll refer to cultipackers longer than 12 feet, with larger diameter packing plates or both as “LHCs” (large, heavy cultipackers).  
What Does a Cultipacker Do?

A cultipacker does quite a few things as it is pulled over soil.   The most obvious are that it smoothes and firms soil that has been recently disked or tilled.  Others, though, are not as obvious.  One less obvious thing a cultipacker does is compact the soil to remove air, which can help reduce evaporation of soil moisture.  Another is that the corrugated surface of a cultipacker’s packing cylinder leaves shallow valleys as it moves across the soil.

These functions are what make a cultipacker such a great tool for preparing seedbeds for small seeds.  As we look at why, keep in mind that the goal is to make the seedbed optimum for small seeds, and that “optimum” means “just right – no more, and no less.”

Optimum” Seedbed Firmness.   Optimum seedbed firmness means that the seedbed should be firm enough, but not too firm.  It should be firm enough for small seeds planted on or near the surface of the soil to stay where you put them and not be driven too deep or washed away by rain.  It should not be so firm, though, that the seedlings won’t be able to easily penetrate the soil with their tiny roots once the seeds germinate.  If the seedling’s roots can’t penetrate the soil, the roots may grow sideways instead of straight down, potentially reducing seedling survivability and drought tolerance.
Optimum” Moisture Retention.  The seedbed should be firmed enough to remove air from the soil, reducing the rate at which soil moisture evaporates.  However, the seedbed should not be so firm that its ability to absorb moisture is reduced.

Optimum” Moisture Availability to the Seedlings.  The corrugated shape of a cultipacker’s packing cylinder leaves little valleys in the soil as the cultipacker moves across the seedbed.  There is also an optimum depth for these valleys—they should be deep enough to help channel rainwater to the seeds and reduce evaporation by wind, but not so deep that water stands in them.

As we’ll see, if a seedbed has been properly prepared by disking or tilling, an FPC will leave the soil in optimum condition in all these areas for small seeds.
Why FPCs are so Versatile and Efficient for Food Plots

Versatility: Weight and Size.  Lighter weight and smaller size make FPCs much easier to load, unload, store and transport.  With regard to transport, some FPCs even come with riding wheels so that the cultipacker can be towed to the seedbed where it will be used.  

Efficiency:  Weight and Packing Plate Diameter.  FPCs are also more efficient at using implement weight to generate pressure against the soil.  Here’s how Matt Kunz of Kunz Engineering explains that.

“A common misconception is that how well a cultipacker can do its job depends entirely on how heavy it is.  Actually, the important consideration is how much pressure the cultipacker is putting on the soil.  That doesn’t just depend on the cultipacker’s weight.  It also depends on how big an area of the soil’s surface the cultipacker’s packing plates are in contact with.  The smaller the area of surface contact is, the more the cultipacker’s weight is focused onto it.  Notched packing plates further concentrate the cultipacker’s weight at the notch points, much like the cleats of a mud tire do on rough ground.”

Obviously that does not mean that a smaller diameter cultipacker is automatically going to firm and smooth the soil better than a heavier cultipacker with larger diameter plates; Matt is not saying that, and neither am I.  Instead, we’re just pointing out the efficiency of smaller cultipackers. Everything else being equal, a cultipacker with smaller diameter packing plates will require less weight than a cultipacker with larger diameter packing plates to achieve a similar soil pressure.

Also, realize that the larger a packing plate is, the more highly peaked it will be, and the deeper the valley it will leave in the soil.  That’s why LHCs with packing plates larger than one foot in diameter leave deeper valleys than FPCs, everything else being equal.  Remember, our goal is to prepare an optimum seedbed (firm enough but not too firm, etc.) for small seeds.  An FPC is the most versatile and efficient tool to do that.  
Cultipackers versus Other Implements

Weighted Drags: As I mentioned earlier (and at the risk of beating a dead horse), your goal is to prepare an optimum seedbed.  If you don’t have access to a cultipacker, you can still do a perfectly adequate job of smoothing and firming your seedbed with a weighted drag, such as a piece of fence with blocks stacked on it to add weight.

If you do use a drag instead of a cultipacker, though, you must understand that drags and cultipackers differ from one another in how much each can firm the soil.  A weighted drag can be used to firm the soil to a great degree, and certainly well enough to plant small seeds.  However, a drag won’t firm the soil as much as a cultipacker.  That’s because a drag floats on the soil’s surface, while a cultipacker presses down on the soil.

This distinction is critical because which type implement you use to firm the seedbed before seeding dictates what, if anything, you should do after seeding.  In fact, it’s so important that it’s one of the sections in the Institute’s small-seed planting instructions that’s in bold print.  It’s expressed different ways for different small-seed products, but they all make the same point:

Use a drag or a cultipacker to firm and smooth the soil before seeding.  If you used a cultipacker before seeding, then cultipack again after seeding.  However, if you used a drag before seeding, do nothing further after you put the seed out.  Do not cover small seeds more than ¼ inch.  Never disk or till the seed into the seedbed.

Notice that if you use a drag before seeding, you should do nothing further after putting the seed out; the seed will naturally settle into good contact with the soil. Never drag over small seeds or disk or till them into the soil; doing so substantially increases the risk that they will be buried too deep to survive.

Also notice that if you use a cultipacker, you should use it both before and after seeding.  In Turning Dirt: Part 3, we discussed how to test to see if your seedbed is at optimum firmness – the “Boot Track” test:  The seedbed will be at optimum firmness if your boot tracks sink down about ½ to one inch in the soil.  If your seedbed is softer than that, then cultipack the seedbed again until it is at optimum firmness before planting.  If you don’t do that and then cultipack after seeding in soft soil, you increase the risk that the seed will be pushed too deep.

Lawn Rollers:  Lawn rollers can do an adequate job of smoothing and firming the soil.  However, their packing cylinders are flat instead of corrugated as a cultipacker’s packing cylinder is so they won’t leave the beneficial valleys I mentioned earlier.

Aerators:  Aerators should never be used for smoothing and firming a seedbed for small seeds.  Aerators will firm the surface somewhat, but they have spikes on their cylinders, which poke deep holes in the soil.  That’s a problem for two reasons.  First, small seeds should be planted on or very near the surface of the soil, and a small seed that falls into deep aeration hole likely won’t survive.  Second, the holes allow air into the lower levels of the soil, which is the opposite of what you want to do when preparing a seedbed for small seeds. Instead, you want to get air out of the soil to reduce moisture evaporation.

Sources for Food-Plot Cultipackers

There are basically two sources from which you can get an FPC:  You can buy one, or you can make one yourself.  

Thankfully, commercially available FPCs are not extremely expensive.  They’re also commonly available from most farm supply stores, farm equipment vendors and even the Internet.

If you elect instead to make your own, keep in mind that you want to use real cultipacker packing plates if possible.  If you make a packing cylinder out of something that has a straight-line packing surface rather than the corrugated packing surface of a cultipacker, your homemade implement may firm and smooth the soil, but it won’t make the beneficial valleys I mentioned earlier.

If you are handy with welding and other metal work, building a cultipacker from commercially available parts will be a fairly easy exercise, and plans are available on the Internet.  For example, see this thread on QDMA’s forum site, which also shows examples of homemade cultipackers built according to the posted design:  http://www.qdmaforums.com/showthread.php?t=16349.

Cultipacker Care, Maintenance and Final Thoughts

The main step you should take to care for a cultipacker is to never, ever pull it with the packer wheels down on a hard surface such as a paved or gravel road, or where the packing plates might run into a rock, stump or other hard obstacle.  If you do, then the packing plates will eventually break.  Most packing plates are made of cast iron, which can break under shock.  Also, when the packing plates are assembled on the axle, some space is left between them to allow them to turn freely; and if you tow the cultipacker with the plates down on a hard surface, the plates will slam together.  Just use common sense - remember, this is an implement designed for smoothing and finishing a seedbed that has been disked or tilled, not pavement, gravel or stumps.  

As for maintenance, check to see whether your cultipacker’s bearings have grease fittings on them.  If they do, then grease the bearing both before and after you use the cultipacker—and do it every time.   And when you add grease, keep pumping until you see grease pushing out of the bearing.  Any dirt or other contamination in the bearing will be pushed out with the grease.  Aside from that, you should try to keep your cultipacker clean and stored out of the elements just as you would any piece of equipment.

Finally, if you’ll be pulling your cultipacker with an ATV, don’t buy a cultipacker so large that your ATV will have to operate at or near the top of its capacity for extended periods.  Doing so can permanently damage the ATV.  If you haven’t bought an ATV yet but anticipate doing so, it can also be a good idea to buy one that’s 4X4 and water-cooled if you anticipate pulling a cultipacker or tillage equipment with it.