How far into ground should disc harrow go? ? ?

[jezreel]

The disk is a secondary tillage tool. To get compacted ground worked deeper, you will need to plow it first. It also helps to add some weight to the disk. I bolt steel plates that weigh about 200 pounds onto the upper frame of my 6.5 ft 3 point disk, which helps it cut deeper.

For larger areas, I use an 8 foot pull type disk, which I add concrete blocks onto for weight. That one maintains better soil contact and requires less passes, but is tough to maneuver in tight spots.

Compacted soil, like you are dealing with, needs to be plowed first. In the following years, you could probably get away with just the disk, especially if you add some weight to it.

My soil is very much sandy loam, and is easy to dig into. The difficulty comes with the weeds that have been growing for years.

So, I want to try to understand. . . my DH is not as deep as it could be, but if I had some decent weight on top of it, it would set further down in the soil? ? ?

 

[wolc123]

Yes, the heavier the disk, the deeper it will cut. I use 100 pound steel plates, held on with 3/4" the rod. My old Ford 8n will only lift my 6.5 footer with one plate added, but I can put 2 on it with my JD 4120, and then it really cuts good.

I also have the serrated blades, like yours has, and they help with the weeds. Another option for that is to spray with gly to kill off the weeds. That will become more attractive when fuel prices get back up there. As long as fuel is cheap, I like keeping my crops "organic", using more passes with the serrated disk to take out the weeds.

 

[jenkinsph]

jezreel,
What other implements do you have to work with that could be used?

I would start with maximum angle/set in the gangs and adjust the top link for optimal cutting with front gangs. Make multiple passes in several directions. Easier after a rain soaks in the ground and you can work it again. Not muddy but not too dry. I use a tiller with my tractor but most people here use a disc.

If you have a box blade or land plane s tine cultivator these can all be helpful in smoothing the field. In the pictures below you can see that box blades and land plane grader scrapers do a good job of smoothing.

 

[jeff9366]

The tandem disk is a secondary tillage tool. To get compacted ground worked deeper, you need to plow first.

Weight bearing on each pan, pan diameter, pan spacing and pan adjustment are the key factors relative to soil penetration.

Most of the Disc Harrow weight is in the pans. A Disc Harrow with 18" diameter pans is too light to reasonably break hard soil. A Disc Harrow with 18" diameter pans requires multiple passes to smooth recently plowed ground even under optimum conditions.

A Disc Harrow with 20" diameter pans is the first weight Disc Harrow with enough weight bearing on the pans to penetrate reasonably well.

An MX with cab should pull a TPH Tandem Disc Harrow with 22" diameter pans covering rear tire tracks through all soil types.

A Tandem Disc Harrow with 24" diameter pans cuts very well, though may be beyond the capability of your cabbed MX to pull at adequate speed.



Disc Harrow gang adjustment:

https://www.tractorbynet.com/forums...ing-three-point-hitch-mounted.html?highlight=


Generally speaking, working moist soil, a Tandem Disc Harrow with adequate weight will penetrate to half the disc diameter, less the diameter of the thick pan hub at the center of each pan. Pan hub diameter varies somewhat between pan manufacturers but usually 3" to 4".

Therefore a Tandem Disc Harrow with pans 22" in diameter, properly adjusted, working moist soil should penetrate to 7" depth on the second pass over plowed ground, smoothing as it goes.

 

[jeff9366]

I would start with maximum angle/set in the gangs and adjust the top link for optimal cutting with front gangs. Make multiple passes in several directions. Easier after a rain soaks in the ground and you can work it again. Not muddy but not too dry.

~~ YES ~~


An MX has a Category 2 class Three Point Hitch. If weight is added to a relatively light Category 1 class Disc Harrow you may over stress the frame and pull it to distortion or destruction. Once distorted the ability to adjust gang angles is lost. I discourage adding weight. Owner added weight is outside the stress parameters calculated by Disc Harrow designers.

Shorten the Top Link and adjust gang angles aggressively for penetration. If that does not do give the penetration you need, you have too light an implement.

 

[jeff9366]

My soil is very much sandy loam, and is easy to dig into. The difficulty comes with the weeds that have been growing for years.

Mow weeds as short as possible, scalp, as the first step.

The Moldboard Plow is a primary tillage implement.

Plowing INVERTS the soil, turning up weed roots to the sun, so weeds roots dry out and die after several days of dry weather. Inverting the soil also brings up small amounts of fresh minerals to the soil surface. A plow does not MIX soil. In the South most would plow about once every ten years.

A Disc Harrow follows the plow. A Disc Harrow MIXES and SMOOTHS soil. Discing without plowing mixes mature weeds into the soil but kills relatively few.

Regardless there are huge numbers of weed seeds in the soil which may take years to get under control through cultivation while immature. PHOTO #2

I have a BIG job in a week or two, discing and dragging about 10 acres. Disc, Disc, Disc all diff directions, then drag, drag, drag.

If you plow moist soil, then let inverted soil lie in the sun for a few days, it should only take three passes with an amply heavy Disc Harrow, adjusted less aggressively after each pass, to smooth plow furrows. Disc Harrow is the smoothing, leveling, evening implement. Many, not all, are satisfied with field condition after discing alone.

Then one or two passes with a Chain Harrow to smooth further if desired. A Chain Harrow does not move much dirt. A "lift" or "framed" Chain Harrow can be cleared of accumulated trash by elevating the harrow from the tractor seat. PHOTO #3

Many planting seeds use a heavy Cultipacker to roll in seeds and perform final pass over field, although a Cultipacker presses shallow, long duration grooves into the soil to retain moisture after rain. PHOTO #4

In any final cost analysis sufficient weight implements provide the lowest operating cost.

 

[jezreel]

jezreel,
What other implements do you have to work with that could be used?

I would start with maximum angle/set in the gangs and adjust the top link for optimal cutting with front gangs. Make multiple passes in several directions. Easier after a rain soaks in the ground and you can work it again. Not muddy but not too dry. I use a tiller with my tractor but most people here use a disc.

If you have a box blade or land plane s tine cultivator these can all be helpful in smoothing the field. In the pictures below you can see that box blades and land plane grader scrapers do a good job of smoothing.

Yes. Have a box blade and I also built a chain harrow out of chain link fence linked between two 10 foot long, 1/4 inch thick, 4 inch diameter pipe. It will be a lot of work. Here痴 my harrow. Not the best, but it only cost $350 to build. I couldn稚 find any used for less than $1K

 

[jezreel]

Weight bearing on each pan, pan diameter, pan spacing and pan adjustment are the key factors relative to soil penetration.

Most of the Disc Harrow weight is in the pans. A Disc Harrow with 18" diameter pans is too light to reasonably break hard soil. A Disc Harrow with 18" diameter pans requires multiple passes to smooth recently plowed ground even under optimum conditions.

A Disc Harrow with 20" diameter pans is the first weight Disc Harrow with enough weight bearing on the pans to penetrate reasonably well.

An MX with cab should pull a TPH Tandem Disc Harrow with 22" diameter pans covering rear tire tracks through all soil types.

A Tandem Disc Harrow with 24" diameter pans cuts very well, though may be beyond the capability of your cabbed MX to pull at adequate speed.



Disc Harrow gang adjustment:

https://www.tractorbynet.com/forums...ing-three-point-hitch-mounted.html?highlight=


Generally speaking, working moist soil, a Tandem Disc Harrow with adequate weight will penetrate to half the disc diameter, less the diameter of the thick pan hub at the center of each pan. Pan hub diameter varies somewhat between pan manufacturers but usually 3" to 4".

Therefore a Tandem Disc Harrow with pans 22" in diameter, properly adjusted, working moist soil should penetrate to 7" depth on the second pass over plowed ground, smoothing as it goes.

Thanks for all the info. I’ve got the DH2572 with 22” discs. So it’s fairly beefy, but I WILL have to figure out how to add weight to that.

 

[oosik]

The far right - vertical picture - looks like you are doing well. I have a light disk harrow. To get penetration I put a 400# concrete cube atop the harrow. It still requires multiple passes to obtain adequate penetration and smoothing.

If I did a whole lot of disking I would obtain a large offset disk harrow weighing around 2000# and costing around $5000. However - the need is not there, neither are the $$$$.

I've considered something like the Brown Mfg Corp offset disks - OSL-900-2422.

 

[wolc123]

A plastic barrel or two and some ratchet straps might work. It would be easy to adjust the weight that way.

Do you have a sprayer ? killing the weeds prior to disking would make it a lot easier to get a clean planting and would save you money on fuel. 41 % gly costs around $8 a gallon and it would only take a couple gallons to kill 10 acres of weeds.
.