Any recommendations or thoughts on tractor implements to do this with a minimum of soil inversion?
Offset disks or a chisel plow seem the most promising options I found in Steel in the Field, but the book leaves a lot of unanswered questions:
How much do each of these two implements invert the soil profile?
What are the pros and cons of towed versus 3-point-hitch versions of these two implements?
There are a lot of variables with disks: notched versus circular, diameter, spacing, angle.
Any guidance on ranges I should be looking for of these variables (e.g. disk diameter 16" to 22")?
How wide a set of offset disks or chisel plow can my 64HP tractor pull through my stony but sandy soil?
I am hoping for a single implement for all my primary tillage:
incorporating market garden residues at the end of the season,
breaking up cover cropped fields in the spring for the market garden
incorporating manure, compost and soil amendments in my pastures and cover cropped fields
beating the crap out of knapweed (I have an S-tine cultivator for the twitch)
Hi Rob! I’m not sure offset disks are considered primary tillage since generally you would want to chisel or plough the soil before running the discs (or they wouldn’t really sink in all that much unless you provided extra weight, but then you run the chance of braking the implement as it’s not meant for primary tillage). Having said that:
Mouldboard ploughing inverts the soil profile from the ploughing depth upwards, chiseling loosens but barely mixes the soil at all (and isn’t meant to), finally offset discs mixes the soil over the few inches that are penetrating the soil (not a straight up inversion).
I’m not sure what the functional difference is between towed and 3pth versions, aside from the fact that if you have a towed one you typically have to have secondary implement hydraulics on the tractor to lift the wheels off the ground (which I do not have on my old Massey, therefore I use a 3pth version). As for the discs themselves, bigger discs go deeper therefore deeper=more horsepower (your soil characteristics will also play a role in HP required). I like the notched discs personally as they are better at cutting into residue. My offset discs is a 2-gang type, notched at the front gang and smooth discs at the back gang. Love it. I’ll try and attach a picture of it here (see below). I can also change the offset angle so that it can be more or less agressive depending on what I’m trying to achieve and current soil conditions.
I’d say consider the HP you’ll need, (see next point) but also availability! You’re better off buying used discs as new ones can be pretty pricey. So whatever you can find easily could be a good choice, and get some spares because you’ll most likely break a few over time! For your reference, mine are 16" discs.
I’ll attach a handy chart for implement sizing (see below also). For your reference, I have a 50HP Massey 65 tractor and pull a 12 disc wide plough (so 24 discs total since I have a tandem disc plough). I can’t remember the size of the spacers between the discs, but it’s gotta be close to 12in. If you do the math, that means my disc plough is about 10ft wide. I have a fairly heavy soil though (silty loam) and I find that 50HP is enough, but not by much in this type of soil. I expect your 64HP tractor could easily pull my disc plough in sandy soil. Also, check out this in-depth document for some good baseline info:
One implement to rule them all would be awesome, and I would have tried to build myself one if I had the time and skills to do it. I know farmers who have combined the chisel and discs to do all of their primary/secondary tillage. But it almost goes without saying that the more you add on (and the wider it is), the more HP you’ll need. And there will come a point where you’re doing more harm than good (if it can be said that tillage does no harm… but that’s another discussion entirely).
I hope that answers all of your questions! Let me know if you have any follow-up questions.
Thanks Denis! The attached JPG looks really helpful and DDA looks interesting. I am still convinced that a set of disks is as primary as I need to get since I just want to incorporate residue and amendments, but you have helped me clarify what I should look for. Now I am ready for auction season.
Indeed if you find that you have no compaction issues in your sandy soil (don’t know how sandy it is), then you could get away with just using the discs to chop up and mix the residue into the first few inches. Glad I could help!
I just heard about the reciprocating spades. If used with a flail mower to chop stuff down first , could this be a viable solution ? Then followed with a rotary tiller of needing a finer seed bed.
Elly
What is your situation? Are you looking at market gardening or field cropping? How many acres per season?
The spaders I have seen are all huge implements. I think there is a lot of mechanical work being done which would mean 1) it would require a more powerful tractor than the same width of disks; 2) there is a lot more that can break down in the implement; 3) the implement probably costs a lot more than a set of disks and a mouldboard plow.
BTW Steel in the Field doesn’t talk about spaders.
There is a place in Ontario that distribute these spaders.
They are made for tractors as low as 20 HP. But yes they are expensive!
But they seem to do less damage to the soil. I’m thinking they could be used as primary tillage , but on a small scale, for example a market garden. So if anyone has any experience with this implement, it would be nice to hear from you.
