DAPNET Forums Archive › Forums › Sustainable Living and Land use › Sustainable Farming › Primary tillage
- This topic has 13 replies, 5 voices, and was last updated 12 years, 4 months ago by
Andy Carson.
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- December 3, 2010 at 8:19 pm #42169
Andy Carson
ModeratorI have about 5 acres were not harvested this year, but where instead disced several times and cover crops were planted this fall. The cover crops (rye/oats/clover/etc) grew well enough and are dusted with snow now, so I have beening thinking about what method I will use for primary tillage next year, as I need to get busy either making or buying implements… I am not interested in using a moldboard plow, partially because I don’t have the power to use a decent sized one, and partially because I am attracted to more conservative tillage methods. The disc I used last year was able to knock weeds down pretty well, but I think I would prefer to have more penetration than what I was getting with this implement last year. I have much rather used my spring tooth (and would love to use it next spring) for primary tillage but it clogs so easily… I wasn’t able to use it at all in my field last year, because it would clog up with cornstalks within 8 feet… So, I am most attracted to either some sort of spring tooth with teeth spaced far enough apart that they don’t clog all the time or some sort of shallow chisel that my single can pull. In concept, these two things aren’t really alot different, but they are used so differently in makes me wonder… Alot of my design and usage of this implement is going to depend on just how deep I really have to go for primary tillage. I don’t see why I would have to go over 4 inchs deep (and hopefully less), but tractor powered chisels usually run at least twice this depth. Do “horse powered chisels” need to do this too? I saw a three tine chisel on the rural heritage website being pulled by a team of 6 heavy horses, so apparently these have pretty high draft requirements too… I suspect it is running pretty deep, but why jnot have more tines that don’t run as deep? What am I missing?
December 3, 2010 at 9:04 pm #63687Marshall
ParticipantI understand your thinking, but I used to have a chisel plow. My ground is light and blows easily. I had a lot of trouble with weeds and someone told me to try spring plowing with a moldboard plow. I tried it and have had less weeds and improved yields. That was about four years ago. I have stuck woth the moldboard plow since.
December 4, 2010 at 12:18 am #63690dominiquer60
ModeratorA disc will work great on winter killed crops like oats and peas. If you have rye, vetch or clover in a mix you may find that a moldboard plow will kill and incorporate these covers better. The Nordell’s use their plow to skim plow at a 3″-4″ depth, it effectively servers the roots to kill and doesn’t disturb the soil very deep, leaving the organic matter close to the surface.
Erika
December 4, 2010 at 1:40 am #63691Tim Harrigan
ParticipantTillage tools like a chisel plow shatter the soil at about a 30 to 45 degree angle from the point up to the surface when they are operated at critical depth, usually 8 inches or so. The spacing between shank is such that the entire profile is shattered. If you run them at four you will not get adequate shattering, mostly cutting some trenches. You will still have to disk, although the disk will get better penetration.
In the attached pdf is a frequency graph for an 8 ft, 16-shank field cultivator with the back 5 shanks out of the ground, so 11 shanks. The first pass was in consolidated soil, the second pass was draft in the same soil as the first pass, so tilled and loosened soil. Tillage depth was about 4 inches. The median pulling force on the first pass was 959 lbf, average was 928 lbf, range was 228 to 1343 lbf. So the average pull per shank was about 84 lbf. Second pass average was 662 lbf, about 60 lbf per shank. This is probably a decent estimate for your conditions, this ground was plowed in the fall and this was in the spring. So I guess your horse could pull maybe 4 or 5 shanks at 4 inches, so maybe a tool 32 to 40 inches wide. That would be quite a load.
The practical problem with tillage shanks is that they are fixed upright and they tend to push residue and plug rather than cut it and clear it. You really need both a wide spacing between shanks and cutting tools that roll to size and clear the residue. A sweep plow might be a possiblity but it would probably take a fair amount of weight to keep it in the ground.
December 4, 2010 at 4:35 am #63695ModeratorThanks Tim. If I use C shanks designed for a field cultivator (about 2 inches wide) and 4 inch wide sweeps running at 4 inches deep, than that would shatter a path of about 8 inches with the more conservative 30 degree spread. These might have a little higher drafts than what you reported, so i would think i would only run 3 shanks. Still 3 shanks at 8 inches each is a span of 24 inches (the evivalent of 2-3 passes with a single horse plow) and I am pretty happy with that! I would put them in a staggered triangular pattern so trash couldn’t hit two at the same time. Maybe some plow style rolling coultiers ahead of the shanks would help with the plugging as well. Heck, they might even reduce the draft a little?
December 4, 2010 at 1:07 pm #63692ParticipantThe field cultivator shanks I used were 2 inch and ran about 4 inches deep. The sweeps will add some draft, probably 10% or so. So it seems like 3 shanks at 4 inches will be a good load. The coulters will add draft as well but help clear residue, particularly something like corn. It will take some weight to keep the tool in the ground, there might be some issues with tracking and stability. Soil moisture will be important. Good luck.
A point of interest, the average travel speed for this field cultivator was 1.25 mph, 1.25 for the sulky plow, and 1 mph for the walking plow. So they were putting out about 3 hp. Less than my chainsaw.
December 6, 2010 at 3:36 pm #63696ModeratorWow, you’re not kidding about the weight Tim. I have been looking at the weight required to keep coulters in the ground for no-till drills, and am getting figures in the range of 400 lbs per disc. In light of this, I think I’m going to use a coulter for only the front shank. Hopefully that is enough to cut and clear the trash, but I’ll have to see. I plan on removing the corn stalks from my field of corn to use for bedding and feed, so hopefully the residue won’t be as much of an issue in the future as it was this least year. I’ll take some pics as the tool is coming together to share. Not sure what to call it… Maybe a mini-Chisel? 🙂
December 6, 2010 at 4:43 pm #63693ParticipantHow about a horse anchor?;)
December 6, 2010 at 5:39 pm #63688near horse
ParticipantAs you’re seeing, primary tillage takes some serious HP – look at 6-8 horses on a 3 btm plow. For chisel plows the est. is 10 tractor HP for each shank. And no-till drills, as you say, are incredibly heavy to be able to bust that surface open with discs.
I wonder how much a sort of “preprimarytillage” would help reduce the overall draft. One obvious choice would be using a disc at a 45 degree angle to the direction the rows were planted. Has anyone ever tried a rotary hoe as a preplanting tool – not for busting sod but in soil that is in a production rotation? The corn trash might be too much for it.
We don’t see those hoes out here much but I do recall they’re good for crust-bustin’.
December 14, 2010 at 4:13 am #63697ModeratorI have decided to call this thing a coultervator. It’s going to be hard to test it with the snow flying like it is now. So that’s a 20 inch coulter, followed by 3 c-shank cultivator tines with 4 inch sweeps. There is about 300 pounds of concrete blocks attached to the front via a length of all thread that is threaded through the blocks. There is room to add more weight if I need it, but I’m hoping I don’t… My biggest concern is the placement of the two wheels in the front. Yes, I put two up there instead of one, mostly because handling that 300 lbs can be tough. Even with the two wheels, it’s not too hard to tilt the implement left and right to facilitate some steering because the handles are so far away from the weight and have good leverage, and because the wheels aren’t too far apart. I am trying to strike a balance between stability and maneuverability with this wheel placement, which can only be a guess without trying it. I am also a little concerned about the height of the coulter wheel, which ended up about an inch lower than I had wanted it (I’m still not sure how that happened). This might not be a problem at all, as I can see an advantage to having the coulter run an inch deeper than the sweeps.
December 14, 2010 at 1:11 pm #63694ParticipantLooks good, too bad the ground is frozen. I think one thing you might want to see if you can find is some low-profile but wider semi-pneumatic tires for the front. They would help with the stability and would not cut in so much in soft ground. It will be interesting to see how well you can control tillage depth with those chisels.
December 14, 2010 at 5:12 pm #63698ModeratorThanks Tim. Thats a good idea with the wider wheels, and it might solve a half inch of my “too deep” coulter issue. I also played with the idea of putting a couple spring tines on outriggers at the rear of this implement, which could act the keep the implement upright and control depth. In the end, I thought I would at least try it with the handles alone as I was worried that too much stability might interfer with maneuverability (If I actually have any maneuverability to lose). The handles alone seem to work with so many other implements (plows, harrow, etc), but these implements don’t weigh 400+ lbs… Of course they usually only have one front wheel too. Another thing that seems to help stability (at least in the garage) is moving some weight from the front to the back. You have less leverage, but it has a more immediate “feel” and this might help too… These are all things that I will have to try when the ground is not frozen and I can see how it feels.
December 17, 2010 at 4:12 am #63689ParticipantHi Andy,
I know I might be getting off your topic but I think you might appreciate this link from Paul Starkey’s book Animal-Drawn Wheeled Toolcarriers: Perfected yet Rejected
Hope it is inspirational.
July 18, 2012 at 3:31 am #63699ModeratorI just had a question about this coultervator I built a while ago. I only used this a little bit, so can’t give a really complete review, but here’s my thoughts. You really do need all that weight on this to cut through corn stalks (and it still pins many!), but this is the only crop residue that I have dealt with that really needs a coulter and weight like this. I haven’t had corn stalks in my field for a few years now, and am predictably less interested coulters proceeding shanks. I think a better design for this without the coulter is to forget the wheels and handles and make a multi-gang implement of skids with adjustable height. I like the one I use with my oxen (see below). I would probably just make a slightly smaller one for a single horse. Nice thing about these c-tine implements is you can add or subtract tines easily if the draft is too high or too low. The handles on the coultervator give OK control, but the blocks make it a bit top-heavy. It kinda takes a horse in the front and a horse in the rear. I couldn’t run it all day for sure. An hour will make your arms sing. When this type of work was new to me, I thought this kind of exertion was fun. Honestly, I still think it’s fun, but i alo realize realize that exertion like this is not sustainable and not an efficient way to get the work done. I think a well designed implement should be easy to operate and this tool simply isn’t. Moreover, this is a tool designed to deal with a situation (unchopped corn stalks lying in the field) that I simply don’t have anymore, and doubt I will ever have in the future. In my current setup, I can’t imagine how corn stalks wouldn’t end up in somethings belly, so having a tool to deal with them seems like clutter. I ended up recycling the parts into other tools, so it was a “waste” or wood, and not metal. Waste is a loaded word, though, it was great experience and I’m glad I got a chance to try it out a bit. Hope this answers the questions…
Here’s a link to the tool I like better. It’s still easy and simple to build yourself.
http://www.draftanimalpower.com/showthread.php?5223-secondary-tillage-tools-and-concepts - AuthorPosts
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