What HP is needed to pull 6 foot slasher through 2-3 ft high Paspalum grass?

Discussion in 'Repair & Technical Discussion' started by Mikefarm, Feb 12, 2012.

  1. Mikefarm

    Mikefarm New Member

    26
    Oct 27, 2011
    Hi all

    I'd like some advice as I'm trying to decide on what HP tractor is needed to pull a 6 foot slasher (bush hog) though grass (often 2 to 3 foot high Paspalum). I'm planning on buying a tractor and don't want to get one that is underpowered but don't want to get one that is too big as its a lot more $ and running costs.

    I have 100 acres, the paddocks are currently slashed by a neighbor with a 100 HP tractor with an 8 foot slasher. It takes about a day to slash a 12 acre paddock when the Paspalum is 3 foot high. (only need to do 3 or 4 paddocks of 12 acres each) Neighbour says that 100 HP would be about right as it can theirs can just pull an 8 foot slasher through our grass when its long.

    I was thinking of going to a 6 foot slasher and getting a Case Maxfarm 60 or a Kioti DK551 or Kioti RX6010 which are about 55 to 59 HP. I'd have to make sure the grass does not get to 3 foot high but slash thrice a summer. Or should I be looking at about 70 HP (Kioti 751 size).

    A smaller slasher will take longer but the tractor will be using less gallons per hour. The 55 HP tractors have a 4 cyl engine about 2.2 litres capacity, but a 100 HP tractor engine is about 4.5 litres so surely it will go through the juice at twice the rate but a 6 foot slasher will only take 8/6 as long as an 8 foot slasher - lets say 30 % longer to do the job?

    Slashers seem to vary quite a bit depending on how thick the metal panels are and the gearbox size (6 foot ones vary from 430 to 650 kgs). I presume that one has to get a slasher with a gearbox rated at or above the tractor HP at the PTO but most sites don't say how much HP is needed to tow it. I know that depends on the load (i.e. grass type and thickness) so that's why they prob leave that out.

    Thanks
    Mike
     
  2. ErnieS

    ErnieS Country Biker

    740
    Jun 1, 2011
    I've run a woods 6 foot bush hog with a 19 HP Kubuta in 18" grass. Not enough power to take a full pass at any speed other than 1st low. My 39HP FarmTrac handles the hog just fine and I can run through tall grass or 1/2 inch thick brush with ease.
    My biggest problem with the Kubuta was going up hill with the mower raised. It did tend to lift the front end. I have no such problem with the FT since it is about 1.000 pounds heavier and has double the 3 point lift capacity.
    50 HP should be more an adequate for a 6 foot bush in my humble opinion. If I remember correctly, Bush Hog has specs on recommended HP for their various mowers. Don't worry about the power needed to move it. That is pretty much inconsequential.
     

  3. Mickey

    Mickey New Member

    Aug 14, 2010
    From your comments I'm assuming you will also be buying the mower as well as the tractor. What I've found in my somewhat limited experience is the design of the mower can make a BIG difference in power needed. With heavy loads, how well the mower can discharge the grass from underneath is a major issue. If the deck can't clear itself, power requirement goes WAY up. With the right mower, a tractor with 35 PTO hp should be able to handle the load of a 6' mower without much difficulty.

    If you can find a mower with no fixed skirt along the rear and with a link chain curtain for safety, that should permit the cut grass to clear itself fairly easily from underneath.
     
  4. Mikefarm

    Mikefarm New Member

    26
    Oct 27, 2011
    Hi all

    Ah, reading Bushhog.com now. Good resource as it has specs for its many types of slashers. I can see for their 286 model which is a 6 Feet one they say a 40 PTO is needed (it weighs 942 lbs so about 430 kg). So a 55 HP tractor should be fine? Its just 5 to HP above the HP required so perhaps I need to go up a bit in HP to not have the tractor in too low a gear?

    286, 6 Feet, 40 PTO, 942 lbs
    296, 6 Feet, 45 PTO, 1,095 lbs

    And yes, if buying the slasher with the tractor I can get one that would match. Not sure what one a dealer would advise but from reading there are lots of differences, gearbox rating, thickness of steel plate, skids or wheels, height adjustment and lots more.

    Mike
     
  5. Mickey

    Mickey New Member

    Aug 14, 2010
    Mike, how about some info on the kind of grass you're talking about. Personally have never heard of it. Is there any other things you have to contend with while cutting or is this a clean field, i.e. grass only? Any intended uses for the cut grass? Wondering why field is not cut until it reached ~2-3'?

    If this is a clean field, there may be better solutions for cutting that take less power.
     
  6. jbrumberg

    jbrumberg New Member

    30
    Dec 5, 2011
    I believe that paspalum grass is used on hot and dry region golf courses.
     
  7. Pipertec

    Pipertec New Member

    187
    Jan 11, 2012
    I wouldn't attempt a 6 Foot Bush hog on less than 45-50 Horse Power. This will let you run the PTO in the low range and not throw things all over the place. It will make it much easier on the engine if you keep the blades sharp cutting thick grasses. I always sharpen mine at least every other cutting. If you run the Bush Hog at High RPMs it will create more vacuum and pick up any rocks, etc. and throw them a long distance. If you are using a turf mower, with smaller blades, use the High Range. This will keep the turf mower from becoming overloaded with grass around the spindle areas of the blade. Although I have an internal clutch on my PTO Shaft, I still use an external Clutch on my Bush Hog. This just cuts down on the wear and tear on my PTO gearing in the tractor. 100 acres is a lot of ground, and I would go as big as practical on my tractor sizing and my Bush Hog.
     
  8. Mikefarm

    Mikefarm New Member

    26
    Oct 27, 2011
    Hi

    Most of the grass is phalaris and we would normally like to slash when the height gets to 2 ft to keep the fire danger low and also when the thistles come up I want to set the slasher to a height to take off their heads and not cut the grass. But there is quite a bit of paspalum which is much thicker and stronger than the normal grass and it that gets to 3 ft high (like it did last week) its a mess. It was a while until I get the next door neighbour in to slash it so it got too high.

    The paddock is a pretty clean field except for about 700 Tagaste trees (also called Lucerne Trees) so it gets slashed between the rows.

    In a perfect world I'd buy a tractor and slasher and always keep it down to less than 2 ft high but if its wet for many weeks over summer and I miss out on doing it then it can get to waist high - that's where the tractor HP required will shoot up. I need to plan for a tractor that will do that.

    Mike
     
  9. Mickey

    Mickey New Member

    Aug 14, 2010
    If the field is clean, using a mower intended for making hay might be a better solution. Something as simple as a sickle bar mower will cut it and not have to contend with the rest of the crop thus taking less power. This will leave you with a crop laying on the ground and i don't know if this is a problem for you. Rotary mowers are not the best thing for cutting heavy crops. Just too much of a load to easily clear from underneath the deck.
     
  10. Mikefarm

    Mikefarm New Member

    26
    Oct 27, 2011
    Hi Mickey and all

    Had to look up what a sickle bar mower was, looks like a long hedge pruner :) Saw some you tube vids of them too. Thanks, I have now learnt about another type of mower. Seem like they are for low HP tractors though. I'm not cutting any crop - its just grass that I don't want it to get too long. The alpacas will be eating it over most of the year but during summer they are not on it and it grows and grows.

    Mike
     
  11. Mickey

    Mickey New Member

    Aug 14, 2010
    Glad to be of help introducing you to new kinds of equipment. Yes, sickle-bar mowers were in their prime when tractors were smaller. That doesn't mean they can't be use with a larger tractor. Just need to be sure mower and tractor use same class 3-pt. One would not want to use such a mower if field included something tougher than grass.
     
  12. Country Boy

    Country Boy Bovi-Sapiens

    Mar 18, 2010
    I was going to suggest a sickle bar mower as well, seeing as you cut the grass at a greater height. A disc mower may be an option as well (designed to cut taller crops). Something like this model might be better for what you are mowing. A used one would be cheaper if you don't use it much, and since it leaves a windrow, you could sell the grass for hay (assuming its viable for hay). Just a thought...
     
  13. Mikefarm

    Mikefarm New Member

    26
    Oct 27, 2011
    Ah the paspalum is a tallish, stong grass with sticky seeds that i want to get rid of. It comes up in summer. Repeated slashing of it should reduce it.
     
  14. sarge1572

    sarge1572 New Member

    17
    Jun 30, 2008
    I don't cut much grass, but wouldn't this be a good task for a flail mower?
     
  15. John R

    John R New Member

    5
    Oct 2, 2010
    Kind of what I was thinking.
     
  16. PSJ

    PSJ Dusty

    50
    Sep 20, 2011
    I've pulled a 6' bush hog for years with a 1955 Ford 600! You don't need 50 hp and up to pull a 6' mower! Unless you want to run it in 4th gear! You can only go so fast with your ground speed for the mower to cut properly, 40hp is plenty for mowing grassy material. JMHO. PJ
     
  17. derbysammy

    derbysammy New Member

    3
    Feb 26, 2008
    I have pulled a 6' bushhog with my John Deere 4710, 41ho PTO with no problem. I use my Ford 671 to pull a 5' bushhog. The John Deere 4710 will also pull a Woods 208 (cuts 106") if the grass is under 7 foot tall. You can operator a 6' hog with a smaller tractor (under 40HP, PTO) but it is hard on the tractor. I use the compact tractor and burn about 1.5 to 1.8 gallons of fuel per hour depending on the height of the grass.
     
  18. Mikefarm

    Mikefarm New Member

    26
    Oct 27, 2011
    Hi all

    Thanks all, looks like I prob can use a 6 ft slasher with a 60 HP machine without problems as it will have certainly 50 HP at the PTO. derbysammy, I think my grass will be under 7 foot tall :) I have read about flail mowers and a few posts on them, seems some ppl like em and some dont'. I'll stick with a slasher type as I'm a beginner and will get what the locals use. Also will be cheaper to start with.

    Thanks
    Mike