Excellent paper, Pars. But it is obvious as tillage burns biomass more rapidly, reducing it and starving the worms.

Interesting... I haven't opened the links, but my experience is just simply what I observe from year to year...

My soil is a very heavy clay with a small measure of loam. Some areas are almost pure clay, with 2 areas of clay that has no loam at all. The amount of organic matter is almost nil.

Now, before I say what I'm gonna say, I will add that such studies seem to focus on large agricultural farm plots... areas long used in farming with varying degrees of good management practices. Right now my garden is only about 1000 sq. ft. of permanent beds - slightly different management styles.

So, that said...

When I first break ground on a new bed, there are very few worms. VERY FEW! In fact, the only real obvious insect life are ants. Since there are so few worms, and the soil is so heavy and difficult to dig, I use a tiller to create the beds (I am getting a bit older, but when I was young I broke ground using only hand tools.) One of the first things I do after the beds are broken is to use a digging fork to turn under as many fall leaves as I can manage - the tiller is only used to create the beds... thereafter, only a digging fork is used. Then, each year, leaves are turned under, and more leaves are kept on top as mulch through winter - eventually I'll switch to cover cropping, but not yet. And, each spring, and at planting time, I turn under as much compost as I have on hand - usually about 1 - 3 inches. The beds are mulched either with organic materials (grass, hay, leaves) throughout the growing season, or another inch or 2 of compost.

A few of the beds on this property are in their 3rd year, some 2nd year, and about half are new. Now... after all this tilling, turning, and additions of organic matter, the oldest and 2nd year beds are brimming with earthworms! Had I not turned the soil there would be very few worms.

What do I learn from my experience? That studies done on large, long-used farm fields, especially those on or near river bottoms or drained wetlands have VERY different soils than small gardens around the world. Are those studies of value? Of course. However, they speak to a certain segment of soil types. Are there other ways of creating permanent beds from heavy clay? Yes, but they are no where near as fast and efficient as the methods I choose to employ.

Will I be able to someday go fully to no-till? Perhaps, but in my climate, organic matter disappears from soil extremely fast. It will be years before I can maintain a soil with such a tilth as to not need large additions of organic matter turned under each year.

Decreased tillage is good for many reasons but it does have a downside in the increased usage of chemicals.

First.. a broadfork is WAYYY beyond my financial ability. I use a very old secondhand digging fork, a borrowed tiller, and a pick-mattock and bow rake I've had for almost 30 years. Second, I doubt very much that even a broadfork would do any good in preparing any new ground here. The clay is extremely plastic, and when dry, is like concrete. It is impossible (I mean impossible!) to dig a hole with a shovel.

As I mentioned, there are other ways to establish new beds, but none are as fast. For example... to use a tillage crop I'd have to cut the weeds back, clear the tree roots from the soil - mostly black locust, sassafras, paper mulberry, and native trumpet vines. Have you ever dealt with trumpet vines? Why do these trees predominate? Because they are favorable to colonization through roots. They succeed because seeds do not easily take hold in this soil. In nature, these trees are woodland pioneers. They are the first to grow in inhospitable soil conditions and create enough humus for seeds of other species to find purchase. Black Locust, for instance, is a legume. It does not need a well established biome fixing, and making nitrogen available. Does this mean that it's 'poor' soil? Not by any means! It is extremely rich soil. It just does not have any organic matter. And there's where a mistake is made... the assumption that there are soil layers to 'disrupt'. This land was pasture for a very long time. Whatever topsoil that was here is LONG GONE lol.

If the benefit of worms and roots is that they help provide natural avenues of transportation through soil, then cultivation is the same process sped up 1000 fold! I am creating top soil! I am taking the top 18 or so inches and creating a soil structure. Instead of waiting on the centuries-long slow motion of nature, I'm doing it in just a few years. And here's another mistaken assumption... that worms are even necessary for healthy soil.

Is there any argument that the N. American continent has been one of the most crop-friendly environs to have ever been farmed in the history of agriculture? Well, to say that it is because of the undisturbed activity of worms is a bit ignorant. Until the Europeans, there were no earthworms in N. America.

Back to cultivating my plots with tillage crops... after the tree roots, then I'd have clear the wild violet rhizomes, cultivate at least a few inches to get any seeds to take root, plant, and wait a season (could be a Winter if it's a hardy crop.) Then I'd have to clear the cover crop and begin with appropriate plants. Now... how much easier is it to till?

See... like I said, those studies are valuable, but extrapolating a 'rule', and trying to apply it in all situations is not in any way practical.

As an example... this idea of less effort on my part... Have you ever taken a piece of virgin land and cleared it for garden use? If you have, you would never have thought to say that a broadfork could replace a tiller and cultivation tools. Just removing tree roots is cultivating the soil! How could I accomplish that task without 'disturbing the natural soil layers'? lol. I suppose I could have used a bunch of glycophosphate to kill the trees and let the roots decay, but... no thank you... the only synthetics I use are a few fertilizers - no 'cides at all.

Studies like that one are very good and there is much to be derived from the information learned, but it's a mistake to take the conclusions and apply them universally. Every situation is different... that's all I really mean by sharing my experience.

Tilling soil introduces air in to the mix which will stimulate the Soil Food Web which will then digest the organic matter (soil biomass) quicker. Tilling also disrupts the structures that fungi have formed which sets them back somewhat in what they do since they now need to form new mycella, part of that mycorrhizal relationship some fungi form with plants. Tilling has also been known to do harm to the earthworms in soil, although some have pooed pooed that idea.

rgreen: I agree with your point that 'it's a mistake to take the conclusions and apply them universally.' As far as I can see, the study basically says that tilling every year in a commercial-scale operation can have negative repercussions - and tilling with heavy equipment at that. You seem to be talking about an entirely different situation: tilling first time out for gardens on land that hasn't yet been gardened, and mostly for soil that has too little organic matter.

So you're likely both right, in the broad sense that one can till too much - and that sometimes tilling makes a lot of sense, particularly when 'first' adding lots of organic matter to soil that needs amending or has just been cleared.

There remains a lot of in-between ground to argue about ))) - and the right answer will certainly depend on specific soil, end-use (commercial or personal), tolerance for / cost of tilling, etc. I'm lazy and like to avoid tilling, but your'e right that sometimes it probably is the 'best' tool. One could over-till, too, and I think some of the newer research about tilling in a farming context is just saying that there's a lot of over-tilling going on.

Where did I say there was a universal rule that must be applied in all situations? I posted a link to a study about tillage and earthworms. I got a response that said "I haven't read the link, but here's why I need to defend what I do against your attack, and why the way I do things is the only possible way I can." I say "Well, have you actually tried something different?" and then get angrily accused of applying a "universal rule."

I'm afraid there is a lot of that kind of attitude displayed on this board - YOU MUST DO ONLY THIS (ps you suck) - but I actually try to avoid it wherever possible, because I am interested in sharing information, not playing dominance games. "Here's some information about earthworms" should really not be seen as such an inflammatory opening statement.

theparsley, I understand, but my comments weren't an attack. They were simply a response on the subject of tilling and earthworms.

The thesis statement of the OP... "We have known for a long time that tillage operations impact large soil
macrofauna such as earthworms, directly by mechanical injury and
indirectly by destroying their channels and burying surface plant
residues..." does not set parameters and limitations to the theme.

Many people, myself included, do not open links. I sanitize shopping cart handles, and I don't drink from open bottles.

Because there were no parameters set in the OP, those of us who read such a posting, and do not wish to catch computer cooties, might read that that thematic statement and conclude a common fallacy... that tilling, plowing, and generally cultivating soil is bad.

I simply, through a narrative of personal experience, presented the reader with an antithesis. Now, I don't think I could have been much clearer that I wasn't attacking the types of large operations being studied, but was simply opening the conceptual discourse on tilling to the many other types of tillage applications.

I never, in any way, implied 'you must do this' (or that you are deficient in some way [my rendering of your word choice.]) In fact, I did the exact opposite. I praised these types of studies and said that my experience teaches the truth that there are other ways of doing things.

Now... this is GardenWeb, a sub-unit of Houzz... most of the people participating are discussing residential gardening, and small scale farming. My comment speaks to the experiences of myself, and other gardeners.

I know when I tilled the garden I am using now back in 2000 it was what I knew and it did help to break up the soil (sandy loam) with plenty of weeds, roots, and more rocks than one can count. And to do the tilling may be a big help for the home gardener starting a new garden area.

I was gifted a book on SFG - SquareFootGardening and about the 2nd yr thought I would try that. I bought cull wood from HD and made frames I laid on top of the row garden area - not filling the beds but just outlining an area where I no longer walked on the soil. I was impressed with how that was working out.

After that I sold the tiller because I no longer used it and haven't tilled since. I don't turn the soil like I did for mom when I was young either.

In between those years I gathered leaves from far and wide to lay and mix in the soil. Tilling at first then just chopping w/mower and leaving on top. I saw an increase in the worms once they had food available - that in turn brought the ground moles to eat said worms.

Also during that time I began composting and only used ferts and pesticides that first year cuz isn't that what gardeners do? Of course it also needed lime - well except where I grow potatoes.

So now I no longer till, turn, or use chemicals - I practice a modified SFG method just using compost and/or compost tea. My plants aren't County Fair prize winners but I have more than enuff to feed us and some friends and neighbors.

IF I had to start today I think I would use the Lasagna Method to suppress the weeds to start then move to a Gumby Modified Lasagna Method (GMLM). Of course you would need to begin preparing the soil the season before. You don't get good results if you try to prepare the soil this week/month or whatever then plant next week/month like they are trying to do at the local community garden.

I think poor planning just disappoints and discourages people.

But just as life is a learning experience so is gardening.

IMO - there is no right or wrong way to garden as each situation/soil/etc. is dyourself.iff.

If it doesn't work this year try something diff next year. Keep notes and enjoy it as you should not be stressing over a garden. You will not find and better food than what you can grow

We all have our own ways of gardening. Sometimes we can learn better ways to do our gardening.

50+ years ago I plowed the garden. Then I disked it up like an 'onion bed.' Then I rushed out and planted and planted.

Later I went to fall plowing and using a rototiller to make rows here and there whenever I wanted to plant. This was an improvement.

Later after a lot of soil amending, I quit plowing. I now have a combination of unbordered raised beds and regular large areas with no pathways. I add a lot of organic matter to different plots in the late summer and fall...and till that in...often ridging rows up for warmer and dryer spring planting. I have a lot of earth worms because they love the recent rotting organic matter.

I do till to make nice loose soil for planting the crops.