No doubt organisms suffer when the soil is disturbed. Some live in shallow habitats while others occupy niches elsewhere. The incorporation of air by turning the soil helps to speed the breakdown of organic matter. The pore spaces in the soil can be destroyed and the structure is altered. Earthworms are often injured and their tunnels are destroyed. The microbes and macro organisms are dealt a blow and the texture is degraded. The compost pile is practically all organic material and the goal is decomposition. Turning the pile also incorporates air which helps the aerobic organisms to thrive as new undigested material from the outside of the pile gets incorporated and the feast for the organisms begins again. Turning the garden soil does not destroy the organisms but disrupts their natural order, degrades soil structure and needlessly speeds degradation of the organic component of said soil.

They have found that farm soil that has been tilled yearly is almost devoid of soil fungi that breaks down woody material to form long term humus. The reason is that the high oxygen input along with mineral fertilizers promoted high bacterial activity and high rates of organic breakdown. The natural soil microbial community found in the forests that created the soils could no longer exist without a long term stable slow decaying form of organic matter.

If you are putting in enough compost it doesn't matter if you till because the microbes have enough to eat. The farms just had the roots and stems from the previous year's crop, which wasn't enough.

A good, healthy soil will have a very large Soil Food Web active and working throughout that soil, not just in pockets or niches. Tilling disturbs this Soil Food Web, disrupts and changes the environment which means it takes time for the wee buggers to get things back the way they were. In a good, healthy soil, tilling is unnecesary. Tilling is necessary in soils devoid of enough organic matter because those soils tend to pack down, they do not have enough air for the soil bacteria to function. Tilling will aid in getting air into the soil, often too much, which then stimulates the bacteria so they work faster and digest the organic matter faster.
Soils properly maintained, those with adequate levels of humus in them and kept covered with a mulch, will not get compacted and therefore will not need to be tilled.
Turning your compost pile does the same thing, introduces air that stimulates the bacteria that are digesting the material you put in there, and the faster they work the more heat they generate, to a point. While it can be good to turn your compost it may not be good to turn your soil.

Disturbing a compost pile is a necessary evil. You cannot use the compost without disturbing it. On the other hand, disturbing your soil can be avoided.

Picture a loaf of moldy bread. When you first see a green spot of mold on the bread, if you leave it alone, within a few days you might have a bag full of the green mold mass. You have thousands of inches of fungal 'hyphae.' The same thing can happen in your soil to create trillions of inches of fungal hyphae. In the soil, that mass of fungi are beneficial and you do not want to kill them. But if you till, that mass of fungi will be chopped to bits all at once. They will eventually come back, but you needn't have chopped them up in the first place.

Hi Gratefulgardener3300,

Let me see if I can give you an example to go along with all the good explanations you have received so far. Lets say you have a candle with a wick that will burn for 7 (seven) days if you light it and leave it alone. Now, chop that candle into seven sections and place water in between each section. Under these conditions, if you light the candle it will only burn until it reaches the water, and then it will go out. Each time you light this candle it will burn until it reaches water, then, again it will go out. This is the same thing that happens to your soil when you till it (only a little worse).

Undisturbed soil reacts in the same manner (to an extent) as the candle. Moisture will rise and fall within the soil, activating the soil food web and providing water and nutrition to any plant found within said soil. As well, organic material that cannot readily decompose (humus) will build up within the soil and store nutrients for said plant. The longer the humus is left undisturbed, the larger will be the amount of storage (bank) one will have. Also, certain fungi will attach to the plant roots and feed themselves and the plant they are attached to. In addition, if the soil is mulched and not walked (driven) on, the soil will take on the composition of Âsponge cake" with plenty of air and open spaces for roots of plants to "mine" minerals and moisture. The soil is a good place to live and grow.

Tilling the soil is like chopping the candle; they both can be rejoined, but it will take some work and time. If the soil is damaged from past practices tilling may be called for to get the soil off to a new start. Then tilling in organic matter and using mulch will get said soil on the road to recovery. The soil could be rehabilitated without tilling, but the process will be longer. There are many roads to the harvest destination; how one gets there is a matter of choice and/or knowledgeÂ

Blutranes

In order be productive soil must satisfy many conflicting requirements.
One of important property of fertile soil  capillarity. Water with dissolved minerals goes up by capillaries to roots of plants. The turning of the soil destroy capillars. Soil must be compacted enough to have capillars. But if soil is compacted it is not aerated.
How to satisfy these conflicting requirements  the capillarity and the aeration of the soil?
Nature gave an amazing answer: soil is compacted but has many holes in it. Compacted part of the soil serves for capilarity and holes serves for aeration. Holes in the soil are formed be rotten roots of dead plants. Tillage destroy both capillarity and holes in soil making it unfertile.

Thanks everyone for the info. I haven't tilled my garden for years now and probably won't do it ever again. I do have another question that might go along with this subject though... The soil I have isn't ideal for root crops (carrots and parsnips especially) and I want to get at least a section of it more suitable to grow these things. How do I go about it? I have nice soil under about 3 inches of sifted compost that I was going to just let sit on top. Now I wonder if it'll be better to mix the OM into the soil?

gratefulgardener3300, what's the issue with the soil and root crops? I assume that the problem would be either rocky soil or heavy clay. If you have rocky soil and really want to grow carrots and parsnips you'll probably either have to used raised beds or old fashioned digging and screening. If heavy clay then consistently add organic matter.

Yeah, my soil isn't clay but it isn't light enough that the carrots grow long. They are short and stubby and I'm assuming it's because of the heaviness of the soil. So I thought that I could amend it with some OM but wondered if I should be tilling this in.

From what I've read it's not too destructive to till clay soil once to add organic matter. That's what I'm planning if the rototiller will make a dent in our virgin clay. From then on I'm just adding OM on top and letting the worms/organisms do the work.

Bacteria love tilling and turning because they get a boost of oxygen and fresh organic matter. Fungi hate tilling because it destroys their complex structure and kills them.

Active compost piles use bacteria to break it down and are benefited by a turn here and there.

Non managed piles or those with high woody content rely on fungi and are best left alone.

Some have active (bacterial) and non managed piles (fungi) running at the same time.

Your lawn benefits from bacteria and fungi. With an organic lawn aeration is usually not a problem and your main goal is to feed the bacteria with organic matter. The fungi will thrive in this environment as long as it is not tilled and disturbed.

I am of the same opinion as GRAYENTRPY, that is I believe that tilling and turnin soil over is benebitial to the plants. Even deep hoeing aroun bigger plant is benefitial for thae.

In the old world, in some parts, farmers would plant wheat on a parcel of land one year and let it rest next year. They did not have chemical fertilizers then and not enough animal manure to go aroun. It has been shown tha if you take two parcels of land next to each other, Till one once or even twice during summer while resting, and do not till the other(a lot of weeds will grow there). Now comes fall you plant wheat on both pieces of land. The following year a drastic difference will be seen between the two. You don't need a chemist or botanist to tell you this. The difference is so pronounced that everybody can see it.

For this reason, if you plant things on a piece of land every year, you turn it over in late winter and early spring. Turning over and tilling does couple of things:
Sunshine does somethin tto the chemistry of soil.and maybe it kills the fungi. Soil gets aerated, that is oxigen gets trapped or attached somehow to soil chemistry. As a result plants benefit from tilling. Now , this might be the result of bacteria benefiting from air/oxygen and creating a better environment for the plants root system. FUngi may not benefit from tilling. That is good news. Plants do not need fungi. Fungie are harmful to plants not benefitial. They might help in changing soil chemistr but at the same time the attack plants root system as well and may cause desease. This is my understandin of fungi role.

Worms also can benefit from tilling and soft-n-fluffy soil that maked their movement much easier.

If you do need to till soil more than once, to make it plantable and to introduce air (compacted soil) then you have not gotten enough organic matter worked into that soil. A good, healthy soil will not get compacted and will have adequate levels of air in the structure without tilling.

Cyrus, tilling does more damage by chopping up worms and destroying their habitat and tunnels than it could possibly benefit them by making the soil soft.

BTW their are beneficial fungi they can keep the bad ones at bay and increase plant vigor and health.

Cyrus,
You said a drastic difference will be seen between the two and you didn't tell me which one would be better. it might be implied but I don't want to assume.

And I asked if I should mix a lot of OM into my little area that I plan to grow root veggies. Should I do this to improve the soil texture so that I get longer carrots instead of the short stubbies I did last year?

Root crops require loose, friable soil to a significant depth in order to develop the long extended roots many prefer. Growing them in heavy, unamended soils will result in stubby, stunted growth. Since they require a good depth of loose soil as well as very good drainage, I'd consider working in a quantity of OM down to 18-24" in at least that area you set aside for these crops.

It's a fact of life that tilling is sometimes required. While nature can build up decent soil conditions over time, that doesn't always occur without human intervention nor does it necessarily happen with the speed most home gardeners require. Excessive tilling is problematic and generally should be avoided but a one time occurrence or the less disruptive manual (rather than mechancial) cultivation of the soil will not overly disrupt soil biota or permanently alter the soil food web.

Walking on your soil will compact it as will heavy snow loads, etc. You'll have to work your soil until you get it to the level of friable that you want. Then, every few years thereafter you may need to double-dig for some reason. This will not kill all the soil fungi - it will set them back and kill a few, but not all.

Think about it: how did they survive for hundreds of millions of years with landslides, fire, frost heave and other disturbance? You don't need to till-turn over every year. But when you do you aren't going to nuke the whole works.

Dan

There is a local organic experimenter in San Antonio who is very successful at growing large potatoes in a raised bed full of nothing but our local shredded "cedar" mulch. It's not really cedar; it's juniper but Texans have never been real precise about naming local plants. When it comes time to harvest the potatoes, he pulls the plant out by the stem and all the potatoes come out connected by the roots.

Cyrus I think you disagreed with Grayentropy. Read his last sentence. Fungi are critically important to the soil. I'll suggest a link with more information below.

Here is a link that might be useful: The Living Soil: Fungi

O' gratefulgardner,

I think adding organic matter to soil that is poor, is very beneficial.

About tilling:
A lot of places, a lot of land neither has worms nor much organic matter. Even if it does, the work begins from the time of plowing/planting till next tilling which take more than a year, ample time. Actually, consider a wheat field. You plow after harvest . that way the straw/hay is mixed with soil, fresh food for micro organisms.

With tilling you get other natural elements to work as well: Air & Sun. I am not too sure about this , but I guess/have heard that sunshine affects the chemistry of the soil, beside killing and destroyin fungi. Fungi are not fun guys, they are mostly bad guys(grin)

...mostly bad guys

I think it depends on the soil. Good soil w/ an active healthy food web could be chock full of beneficial fungi and very little that are ''bad guys''. I have at least 13 strains of Mycorrhiza that are there because I put them there.

Fungi are not fun guys, they are mostly bad guys(grin)

This is so NOT true!! Soil fungi make up one of the most important and largest populations in a healthy soil food web. While there are some 'bad guys', they are in the distinct minority as the majority of soil fungi - multiple thousand different species - are beneficial and absolutely essential to the process of decompostion, the breakdown of chemical pollutants, providing plant nutrients and combating parasites and pathogenic organisms. In fact, you cannot have a vibrant, healthy soil, and therefore vibrant, healthy plants, without them.

To think otherwise - and attempt to destroy soil fungi - is a huge mistake! Cyrus, do yourself a favor and read the link provided and many others you can find that explain the vital and absolutely essential role fungi play in our lives and in the soil.

Grateful gardener, I have the same short, stubby carrots. It's easy to say don't till your garden, but how else do you incorporate organic matter into the soil? Or loosen up the soil so that you can have normal carrots? You have to start somewhere. I have part of the veggie garden in lasagna garden but when I dig through the 2 years lasagna, the clay soil in this area is exactly the same as it was when I began the experiment. Clay. And, I have lots of worms. My soil goes from too wet to stone very quickly (I think I have a 20 minute window to prepare it at planting time). And, I don't walk on the places I am going to plant so that isn't compacting it.

I have been top tilling every year. During the winter, I pile on all of the container soils from my container grows, cut down ornamental grasses, and a good 8" or so of leaves. If I didn't till this mess into a workable top layer, I would have a mess. During the winter, I could scrape off the layers of OM and dig 8" down and find a layer of worms, and nightcrawlers. Sometimes there would be as many as 40 in the shovelfull of soil. I hate to disrupt the soil web, but still need much more OM in the clay soil that I am stuck with. The top layer - 10-12" or so is wonderful, but underneath is still a mess. Kimm and others, do you think I should deep till this one time now, and then just top dress from now on? I still plan on adding all the container soil from each years grows. Thanks TiMo