hedwig, I am an ardent supporter of digging (tillage). Here's why.
1. Turning the top 6" of soil completely over buries weed seeds and OM and exposes the 'subsoil' to weathering. Over time this practice improves the cultivation depth (rooting zone) physically and biochemically.
2. Higher yield of crops is related to deeper tillage (up to a point). In sugar cane agriculture, flood fallowing results in greater depth of tillage than mechanically prepared land of the same soil type. Flood fallow 'tillage' yields are consistently higher than those obtained after mechanical tillage.
I have adopted the motto of the Royal Agricultural Society, "Practice with Science" so if I learn it, I do it.

There is no-till cotton farm in West Texas that apparently does great with no supplemental irrigation. It recieves around 15 inches a year and they spray the ground with mollasses 3 or 4 times a year. That's it. MUCH less work than neighboring cotton farms that employ till method which uses supplemental irrigation due to ruined soil biology from tilling.

No Till method WORKS if you have the knowledge of how,what,when,why it works.

It is not so much "digging versus no digging" as to till or not to till. Tilling the soil may be necessary sometimes, but if once tilling is done and the soil is properly handled after that there is no good reason to till again.
Tilling, rather than burying "weed" seeds, turns "weed" seeds that have been buried for a long time. Tilling disrupts the life cycle of the soil bacteria, and destroys fungi mycelum that only exist and work well in untilled soil. Tilling is not inherently evil but for most gardeners is unnecessary, if the soil is kept in good condition with lots of organic matter in and on the soil.

tilling damages the soils structure for no real gains and a lot of energy imput, it also allows for loss of moisture from the soil and can add to errosion by wind and water problems.

there are farmers using no till practises and getting what they say are real benefits in soils structure and build up of soil instead of loss of soil, also some farming practises are using a minimal till process where they don't actually turn the soil over but just open it up.

but as in nature there is no tilling of the soil apart from worms and other bugs etc.,. the whole purpose of no-till is to replicate nature in that simple way. we have used no-dig for near on a decade now with very good results and none of the toil or noise or pollution caused when using machinery.

but if someone is hooked on tilling then that is their lot and their choice.

len

Here is a link that might be useful: len's garden page

thanks for the anwers!
I've got further questions:
1. tilling = ploughing?? and is hoeing in a garden the same than a farmer that tills (or ploughs)?
2. What's the story of molasses? is it a fertilizer? does it make sense in home gardens?
3. How do you prepare a fine seedbed with no dig methods?
4. Who invented the no dig and no till method and has it been used raditionally?

I've dug my suburban soil over once and it was quite good because I dug out: concrete, old pipes, a battery, garbage, and heaps of big and small stones. the no dig- methods I read about let the soil alone and do not use the soil underneath at all.
5. Are there two different methods: one no dig with raised beds and the other no till?
6. further reading?

ouff many questions, but good answers create more questions!

hi ronalawn,
is flood fallowing green manuring? and is green manuring for you tilling?

Further question.
1)Tilling = plowing, same thing. Hoeing may not be the same depending on how extensive it is. Hoeing can be equated with a farmer culivating a field, just stirring up the soils surface to control "weed" growth.
2) Molasses can be a plant food in a soil that has not reached the good, healthy state yet. Generally if your soil has been well amended so it has a good working Soil food Web and is good and healthy molasses will do nothing for the plants growing there so it is not needed.
3) If you have developed your garden so it has good, healthy soil that is the seed bed and all that needs be done is move aside a bit the mulch that is on that soils surface.
4) No till evolved over many years from the ideas of many people, although a prime mover might be Edward Faulkner with his "Plowman's Folly".
5) there are no differences except those that make raised beds do a lot of work to get those beds raised which those of use that use surface level gardens do not have to do.
6) the link below is one of many similar papers.

Here is a link that might be useful: No Till Reasons

hedwig, flood fallowing consists of flooding the area with fresh water for a minimum of 6 months to a depth of at least 12 inches. It is a neat application of biochemistry. A prerequisite is that the soil must be rich in iron content. The flooding sets up anaerobic conditions in the soil profile as far as the water will go down. Under these conditions, the iron compounds are changed to the ferrous form which is soluble. All the soil particles get covered with this compound and the mass turns blue - a visual indication of the progression of the reaction. After at least 6 months the water is drained off and as the water table recedes in the soil profile air is drawn in and the ferrous compounds are oxidized to the ferric form which is insoluble. This results in a tilth (soil structure) to a depth that 'will satisfy the most exacting market gardener' and this occurring in soils that are not unlike concrete when dry and as structureless as a bar of soap when wet!
If you are interested in finding out more, your best bet is to look in the past reports of the proceedings of the ISSCT.
To answer your question, flood fallow is only incidentally green manuring. Fields were flooded immediately after harvest and all vegetation of every color was broken down in the process. Fish life proliferated and that aspect is at present actively pursued as an added benefit. I would hold it up as the best example of a truly organic, all-in-one alternative to mechanical tillage, weed control, animal pest control and reduced nitrogen application.
Finally, green manuring is tillage within the context that tillage is the creation and improvement of root depth.

everybody has to do work to create garden beds but those of us who use the raised no-dig idea do that work once and once only, the dominators who till and plough and have strong backs, do that at least once a year if not twice. all raised bed gardening is doing is mimicking nature.

if you green manure then it needs to be turned in or similar the similar being pull it (or alternatively cut it at ground level and leave the roots in the soil to rot and cover the top growth with hay) and lay it then cover with a hay type mulch, but then if you use hay type mulches all the time as we do green manuring is not needed as our plantings of green beans help there plus the hay has nutrients it releases as it breaks down..

hoeing doesn't dig as deep as tilling generally but it all comes under mechanically assisted turning of the soil, and not necessary.

the times i've planted seeds in our beds i just pull aside the hulch a little sprinkle the seed along the row and lightly cover with some old potting mix whatever.

if you dug up an old battery i'd be wondering what else may be hidden in your fill soil??? and also whether the soil is contaminated? all the more reason to leave well enough alone and go for raised beds to try and create a safer growing medium. the old acid from that battery will have leached into the soil i would suggest. also wondering how the developer got away with that sort of fill?

len

len