Haven't posted anything in a long time so thought a thread on tilling might be the occasion...
I'm a full-time farmer like Zasso Noka so I'm used to working with a lot more ground than might be the case for most people on this forum (2 tanbu up and running for this summer, teo more for next spring, then working up to a full hectare sometime in the next three years). I'm basically intending to go full no-till, but have opted to use a borrowed kanriki (an ancient crank-start diesel Iseki that weighs a ton) to get my beds formed: I'm currently growing vegetables on eighty-five 5m x 75cm permanent beds and will be up two hundred and ten in the next three years, with another seventy-five or so devoted exclusively to perennial herbs, and it would take just too long to do that all by hand.
For info, here's how I've been going about getting my beds ready:
1. cut the - very long and dense - grass, pulling it to the side and separating dead and green (to turn into compost later which I spread on the surface - I don't want to work the dead grass directly into the soil as in order to decompose it consumes both nitrogen and oxygen which I would rather make available for my plant roots).
2. marking out the rough area where my beds will be (I don't see the point in wasting time ploughing an area I won't be planting in).
3. using the Iseki to cut up the topsoil (the land is unused - for the past ten years at least - terraced rice paddies so it's pretty hard), going over once, twice and three times, going as deep as I can.
4. marking out the exact bed placements with string and bamboo stakes (which I leave in place so I can re-attach the string when I need to reform the beds in the future)
5. raking off the residue that has come to the surface as a result of the tilling: stones and roots, mainly.
6. going over the beds with a broadfork (I use a crafty gatherer from New Zealand) to work the subsoil.
7. going over the beds with a fork (a spear and jackson I brought back from the UK), pulling out all the residue that's left: stones, roots, roots and more roots mainly.
8. raking the beds flat (with an "american rake" from the farmers' store when the soil is still rough, with a spear and jackson landscape rake when it's finer).
9. throwing down lots of organic chicken manure and compost.
This might seem like a lot of hassle (it is) but it does cut out a lot of effort once the initial work is done, saves money on equipment, and is above all very beneficial to the soil (both enabling micro-organisms to flourish, and avoiding the drought-flood cycle increasingly evident on industrially farmed land.
As you can probably guess, I personally do not see the need to buy an expensive tiller (or indeed to even use or own one once once the intial work is done). I think that the mania for bigger, faster and more powerful kanrikis is the same as for most farm equipment: it's hype. There really is no need for soil to ressemble chocolate powder (this really marked me when I first visited farms in Japan: nowhere on any of the farms I had worked on in France did anyone see the need to till their soil that fine) to grow stuff in it. Some of the soil on my farm quite frankly strikes me as being better suited for making pottery than growing stuff in it, and yet barley, tomatoes, cucumber, pumpkins are all growing in it. Nor, as I said, is there any need - or indeed any point - in ploughing an entire field: you only plant in a relatively small percentage of the soil so why waste time and energy on ploughing soil that will only be compacted by being walked on it or drivien over, or indeed just sit there unused, the perfect environment for passing weed seeds?!
Not only that, but constant tilling can be very damaging: I worked for a year as an apprentice on a farm here in Nagano and I will never forget the effects I observed of constantly bringing stones and weed seeds to the surface, and creating an impenetrable hardpan where the tiller blades turned, preventing water and plant roots from penetrating.
When you take all of that into account, I really do think the best thing to do is to borrow (or buy cheap) an old and simple kanriki, use it get started, then neve touch it again.
If you are that way inclined, there are complimentary techniques you can use to speed up the beneficial effects of no-till on your soil:
- tarps: the Americans use sillage tarps, I use 0.15mm 育苗専用遮水シート 3m x 55m which I cut up into 3m x 6m strips to use on my beds to prevent weeds from spreading and help decompose plant residue
- green manure: rye, barley, soba, wheat, vetch, clover etc. to build nitrogen/organic matter in the soil. Some people dig it in. or you can just lay it down on the surface and let worms do the rest. And use tarps to speed up the process.
- gas burners: to burn weeds as the begin to grow, creating a stale bed. Neversink farm in the US has developed what looks like a very good model, Shinfuji here in Japan sells a similar version (not available in the shops it seems) that has four burners you push along your bed.
Sorry for the long answer - and all the unasked for information - but, as I said, it's been a while since I was last on...