Teach me about mowing width & PTO requirements

[flusher]

I've been going through just about 20 pages of threads, but haven't found an answer yet. So i hope you can either point me to the thread i couldn't find that talks about this, or maybe educate me (and potentially others!) Thanks in advance.

We're looking at getting a rotary mower at some point in the near future. We have 5-7 acres of established pasture & "lawn" to maintain, most of it fenced in. We need to mow a handful of times each year (the rest is done by the horses ). There is no heavy / thick brush to cut through, no trees / saplings or anything like that. It's grass and some weeds with stems potentially, but most of it shouldn't be anything a regular beefy lawnmower couldn't take care of i think.

I have some question marks swirling around in my head (plenty of room in there next to the pea size brain ) about mower sizing etc.

First of all, should the mower be wide enough to cover the tractors tracks or not? The good thing about a mower being as wide / slightly wider we thought would be that you can get closer to fences to cut the grass right up to the fence. If the mower is narrower than the tires, you can't do this nearly as easily, if at all? Or can you?

A wider mower however has some clearance issues when you get right up on the fence i guess? When you try to steer away from the fence, the mower swings towards the fence? And thus a narrower mower would be better?

Then what about the grass that's been pushed down by the tractor tires? If the mower is as wide as the tires (and we're talking outside of the tires here, not inside of the tires?), is it even going to cut the grass that the tires just crushed? If not, we might as well get a mower that's as wide as the space between the tires then instead of wider?

Secondly - What about PTO requirements? I saw on the Bush Hog site that some mowers had a PTO HP requirement listed of something like 25-50HP. That's quite a range! What's up with that? I guess that's related to the thickness of the brush you intend to chop up with it? For our situation, i think we don't need a heavy duty type of mower, and thus we can get away with a lower HP model?

And then finally - When you combine the two things above (width & HP)... If you say we should get something as wide or wider than our rear tires, that means going with a 6' mower. 6' mowers require a little more HP than a 5' one. What's the minimum model mower (in terms of HP) we should expect to be looking at?

Thanks!

I mowed about 7 acres of flat pasture land with a 4-ft medium-duty King Kutter brush hog and a Kubota B7510HST(21 hp engine, 17 hp pto). Tooks 10-11 hours when the weeds were 3-4 ft tall; 5-6 hours when 1-2ft tall. With 26 hp, you could step up to a 5-ft medium duty hog with no problem. No need for a heavy duty hog since you're not cutting brush and saplings.

The wheel track on that Bota is about 46 inches, so the hog just barely covered the tracks. And yes, the weeds/grass will be flattened by the wheels, may not spring upright and the mower may not cut these tracks as short as you would like. That's a price you pay for having your mower hanging on the rear of your tractor. Best solution is a front mounted mower like some European tractors have. But these are pricey. Or, forget about the rotary mower and get yourself an old sicklebar mower if this is a problem for you. I plan to turn my pasture into a hayfield and have a neat old Allis Chalmers 82T tow-behind sicklebar mower that I bought locally for $150.

I tow it with my Mahindra 5525 (54 hp engine, 45 hp pto, shown in the photo), but would be easily towed by your tractor.

 

[Ray_Fort_White]

I'm in a similar situation. 5 acres in North Florida, 2 are lawn and the rest former pasture. I've been mowing with a JD LA120 Mower but it beats me to death, takes 5 hours, and the blades get dull after 3 mowings. I'm so low to the ground that I eat a pound of dirt each time I mow. I'm looking at JD 3005, 3032E or 3038E. One dealer said that a 5' cutter was as big as I should go on that weight of tractor. I was hoping to go 6' medium duty bush hog. How much does the weight of the tractor affect cutter size?

I don't think a finish mower will hold up. The former pasture went un-mowed for quite a few years and was bush hogged a year ago, right befor I bought the place. There are 3" stumps everywhere. Turtles have burrowed in numerous places making it a bit of a roller coaster ride. I might need to disc it or something to get it smoother.

I'll keep the riding mower to do around the house and out buildings.

 

[john_bud]

If you look in the owners manual for your machine it will tell you what is the largest attachment of each type and some basic settings for top link attachment etc.

I would bet that your tractor lists a 5' rotary cutter as the largest it will handle. The usual rule of thumb is that a bush hog (rough cut mower) takes 5 hp per ft of width. A dedicated finish mower takes MORE hp as there are drastic differences in the design of the deck, number of blades, blade design etc. Since you are only going to mow a handful of times per year, a rough cut mower is probably the best choice. Since you need to cut out to the fence edges, you could use a 6' cutter. A Woods Brushbull 72 light duty cutter would work. The equivalent Bushog brand would also do a fine job. People will argue about which is better (like Ford vs Chevy trucks!). But in reality, both are good. Landpride also makes a good cutter. Going with the 6' cutter will stress the tractor out, but you can slow down on the initial swath and take narrower cuts. Using blades with LOW LIFT will reduce the need for hp. Not cutting when wet with dew or rain will also aid you.

King Kutter and Howes make a lot of the low end cutters. They are ok. May be fine for you, but quality does track price --> how much you want, need and can afford is up to you. I prefer to buy higher quality stuff as it tends to work better longer with less issues. I think that both KK and H make a line of medium duty / heavy duty cutters that are special order. They are basically equivalent to the light duty high end cutters. (some will dis-agree, but that's my opinion!)

jb

 

[IslandTractor]

Now consider a flail mower also. Look at threads here for some thoughts. Might be your best options.

I agree. Cutting a pasture is perfect for a flail. You can have a slightly wider flail than rotary cutter (brush hog) using the same HP. As you are not intending to get into heavy brush, you could handle a six foot "medium duty" flail like a Caroni FM1900 for your pasture cutting duties. Cheaper and less delicate than a RFM and gives a better cut with better manuverability than a rotary cutter. Safety and storage space advantages to consider too. I used to have both rotary and RFM but got rid of both and just use the flail now.

 

[kthompson]

I'm in a similar situation. 5 acres in North Florida, 2 are lawn and the rest former pasture. I've been mowing with a JD LA120 Mower but it beats me to death, takes 5 hours, and the blades get dull after 3 mowings. I'm so low to the ground that I eat a pound of dirt each time I mow. I'm looking at JD 3005, 3032E or 3038E. One dealer said that a 5' cutter was as big as I should go on that weight of tractor. I was hoping to go 6' medium duty bush hog. How much does the weight of the tractor affect cutter size?

I don't think a finish mower will hold up. The former pasture went un-mowed for quite a few years and was bush hogged a year ago, right befor I bought the place. There are 3" stumps everywhere. Turtles have burrowed in numerous places making it a bit of a roller coaster ride. I might need to disc it or something to get it smoother.

I'll keep the riding mower to do around the house and out buildings.

If I were using a RFM in rough ground keep the wheels clear, let it ride on the 3 pth hitch. The larger tractor tires will not be as hard on rough ground as smaller diameter mower tires or even those on a RFM.

Based upon what you said about your pasture, get the stumps out and then level it. Depending on the how bad it is, you may be best to haul in some dirt and fill in if a few holes or disk it and level. If you like the grass that is there and don't over disk it, the grass will normally come back right well. If you don't like what is growing there kill with such as Roundup and then disk it and reseed. As to eating dirt..often means grass not covering the ground or mowing too low. As to dull blades, 7 acres mowed 3 times is 21 acres. That seems like your edge is holding up right well to me if mower blades.

 

[teg]

Flail mower (if you can afford one) would be my first choice. It hangs close to the rear of the tractor and does not tend to Fling objects far if you hit something. I don't know about a rear finish mower but the way you talk about the pasture, I think it would be my second choice and should work. The rear brush hog would be my last choice if I had horses nearby and fences to play with. It sticks way out there and can fling a rock about a county mile.

john_bud, I thought generally, a rear finish mower uses less HP, so that you can actually use a larger one (vs. a shredder) for the same size tractor???

 

[IslandTractor]

Flail mower (if you can afford one) would be my first choice.

So long as you don't buy a heavy duty flail, the prices are quite competitive with RFMs. I believe the Caroni TM1900 (75 inch) can be had delivered for under 2K and for about $1700-1800 if you pick it up at AgriSupply. Hard to get a good quality RFM for those prices.

 

[have_blue]

Just remember that if you let your grass get away from you, a brush hog won't mind, a RFM will be a big problem.

And don't say your grass won't ever get away from you.

 

[Diamondpilot]

I am like most of the others. I have a 28HP tractor, 25HP on the pto and run a 5' Ford Bush hog no problem and a 6' Caroni RFM with plenty of power for both.

Chris