Single shank ripper 28" - 30" WORKING depth?

[jake98]

That sure sounds like you'd need a bigger machine, to me. A little back hoe would do it tho.

 

[jenkinsph]

I agree that parabolic is probably a better chouce for the working depth that I need. I have access at work to a plasma cutter and mig welder, so building one is an option.

If I were to build a parabolic shank, I guess I would need to cut several pieces out of plate 1/4" to 3/8" thick each, and laminate them together?

I would cut the shank out of a single piece of plate steel. Why bother with laminating? Seems that would just add to the labor and welding time. I should add that you can use some of the drops in building the rest of the implement.

Last time I built one for 24" working depth I used 1" plate and made a template out of cardboard, then cut it out with a torch.

 

[Reg]

It is nearly 30 years since I took much interest in vineyards.
At THAT time running a mole plough down to 2 ft was widely recognized as adequate.

I guess I'm having a little problem getting my head around the idea that there is something critical between 24 and 28 inches ?
For vines you need good drainage between the rows, no doubt, but the difference between 24 and 28 is probably a lot less than between pulling a mole through and not pulling a mole.

 

[sixdogs]

Brillion has a single shank sub-soiler that I looked at last yeat. There is a short shank and long shank version and the long shank has 35" of ground clearance.

Brillion Farm - Sub Soiler

I happened to find a used single shank short clearance and wanted it for both cat I and cat II. The way I solved the ground clearance issue was by changing the mounting arrangement. Here's a link to my thread and in the second or third page you can see the side brackets and how they give me extra ground clearance by lowering the hitch pins. You would likely be OK with clearance by shortening your lift arms but I wasn't. Here's a photo as well.
I only rip 12"-14" deep but it's easy to go to 24" with a bigger tractor. Not sure you could go that deep with yours but maybe if the ground is firm and tractor weighted. Watch out for rocks and underground hazards. Good luck.

 

[Kirboid]

It is nearly 30 years since I took much interest in vineyards.
At THAT time running a mole plough down to 2 ft was widely recognized as adequate.

I guess I'm having a little problem getting my head around the idea that there is something critical between 24 and 28 inches ?
For vines you need good drainage between the rows, no doubt, but the difference between 24 and 28 is probably a lot less than between pulling a mole through and not pulling a mole.

The agri-science side of viticulture has changed alot in the past 10 years. The mole is still a recognized technique to improve drainage, it is done between vine rows. The problem with the mole is that sooner or later the tunnel collapses. I will be installing permanent drainage tile using 4" perf'd drainage pipe between every third vine row.

Ripping the vine row itself prior to planting improves drainage in the rooting zone, but that is not the primary purpose. The main reason this is needed is to break a dense clay layer that averages around 28" to increase the effective rooting depth. If it is not ripped, the roots will not easily penetrate past this layer. In a layer like this, ripping does more than just slice a cut in the layer. Wingtip ripping creates upward pressure on the layer and fractures the layer to the left and right of the rip itself - as long as it is done when the soil is not too moist.

The depth of the layer was identified by using an electronic soil compaction/penetrometer probe and a soil survey (first photo) with observation of mottling (second photo - horizontal accumulation of mineral deposits, indicating a drainage restricting layer, i.e. compaction).

Ripping at 24" would be above this layer and not accomplish the goal of improved effective rooting depth. Should anyone be interested in diving deep into this topic, here's a good USDA pdf.

Why spend the time and money on this? Studies have shown that it improves vine health and drought resistance, and increases yield 5% to 15%. For a crop that yields $4000 - $6000 per acre, the payback is clear.