hp requirements for disking

[MarshValley]

The implement brochures give widely varying info on how much hp is needed to pull a disk, generally from 5 to 10 hp per foot, which is quite a variation. I'm shopping for my first tractor, for a five acre old walnut grove and building site. Soil is black adobe tending toward dg. I will mostly be rough-cut mowing and moving material around with a FEL, but think I will also want to disk. Terrain is nearly level. Do I really need 40 hp to pull a 4-foot disk? Is that total hp or PTO hp? I'm leaning toward Kubota, JD or NH because of proximity of dealers. Any thoughts? Thanks, NE

[JoeinTX]

For a disc/chisel/plow, you're looking at engine HP. Also weight and traction. A 40HP tractor can handle anything from a heavy 5' 3pt disc to a lightweight 10' drag disc harrow depending upon conditions.

In general.............a 40hp 2wd tractor mated to a 6-7' mounted tandem disc is pretty safe. You probably won't know for sure until you get your tractor and a disc out there on the place and try to do what you want to do with them to know for sure.

[Reg]

You need draw bar horsepower and to get that you need WEIGHT to the ground.

The weight of the disk, the soil conditions and the angle of the disks determine how deep it will cut - which, together will the speed you pull at, determine HP needed.
If anything you should be surprised that the range of HP requirement is ONLY 2:1
(-:

[jenkinsph]

MarshValley,
From your description of work I would consider a 30 hp tractor with fel, rear brush mower, tiller and boxblade. I would recomend a simple drag to smooth out the tilled ground.

Using a tiller will reduce the number of implements you need to get a good seedbed. It will also allow you to select a smaller more compact tractor as well since the need for higher traction is eliminated.

[foggy1111]

In these small tractors its ALL about how much weight you have.....as they will spin out before lugging the engine down in most cases. Then too.....a heavy disc will cut deeper which requires more weight and power on the tractor....and so on. It's extremely hard to give a hp requirement because of so many variables.

A tiller can be a better implement for working the land with these little tractors. (here the 5 hp per foot requirement seems to be right). I have both tiller and 5 1/2' disc.....and prefer using my tiller if I don't have allot of rocks and stumps to contend with.

[Egon]

Depends a lot on the type of disk. The site below will list some serious agricultural disks and what it takes to pull them.

Model 155 Single Offset Disc Harrow

[Soundguy]

a ford N can easilly pull a 6.5' 3pt disc.. or a 8' pull disc. N were about 27 pto hp ( later ones ).

now. that said.. the weight of the disc, and how agressive you have it set, along with actual soil conditions will dictate how well it pulls, how deep it goes per pass, and how agressing you can get.

soundguy

[MarshValley]

Thanks for the comments.

Another consideration, also partially hp related, is using a blade. Some tractors can take a front blade; all can take a rear blade on the 3-point. My terrain is nearly level but also somewhat hummocky, and will be more so after I pull some trees. How do rear blades, box scrapers, and front blades compare for light-duty grading? Seems like a rear blade would be harder to use. Is a box scraper of equal (or greater?) utility for grading? Thanks, NE

[Soundguy]

box blades are good for moving dirt and general flattening of land. grader blades are more for road maint, or finish grading.

if you hook a stump on a grader blade.. I expect it to bend easilly. can bend a box blade by hooking a stump sometimes too.. especially the lighter ones. remember.. adding a blade to a farm tractor does not make it a bulldozer.

soundguy

[Reg]

Thanks for the comments.

Another consideration, also partially hp related, is using a blade. Some tractors can take a front blade; all can take a rear blade on the 3-point. My terrain is nearly level but also somewhat hummocky, and will be more so after I pull some trees. How do rear blades, box scrapers, and front blades compare for light-duty grading? Seems like a rear blade would be harder to use. Is a box scraper of equal (or greater?) utility for grading? Thanks, NE

Tractors ain't dozers, so front blades tend to be hazardous to some FELs if used as dozers.
Box scraper is easier to use and I think easier to learn.
GENERALLY a Cat 1 tractor cannot cut hardpack soil without first loosening it.
I use the box scraper with scarifiers down for the first loosening pass over the high spots that I want to take down.
If it is TOUGH and very hard packed I might only use the middle 4 or 6 scarifiers a) to be able to rip through at all b) to reduce the turning moment if an outer scarifier catches something really tough.
So yes, there is greater utility in a box scraper.