I'm preparing to start a garden in our back yard and am pretty new to growing things... I am confused on the tilling vs. not tilling issue. I've read that tilling damages soil structure and causes runoff and soil erosion. All sounds like stuff I'd like to avoid....however, most agriculture is done in tilled soil and there's clearly a reason for this.. What is everyone's take on this issue?
Our soil isn't great so we'll need to add some compost and other stuff to it, is there a way to do this without mixing it into the soil? Compost tea and mixing nutrients into liquid somehow?
The trick is that stuff does about 3 to 10 times better in tilled soil.
The flip side is that every time you till the soil, 30% of your organic matter piffs off to the atmosphere. Replacing that organic matter can take dozens, or even hundreds of years! And if you do it over and over, your soil slowly turns into dirt - or something resembling cement.
Introducing the raised bed. If you build it all enough, you don't need to ever till. And because it's raised, you have this inclination to not walk on it. And because you don't walk on it, you don't need to till it!
Thanks Paul, that's really helpful. My one hesitation with building raised beds is that I'm wanting to explore the potential of agriculture to improve soil conditions, which I can't do if I'm not working with the original soil. Why do plants do so much better in tilled soil? Is it easier for their roots to spread or moisture to penetrate or..? What does tilling accomplish?
I see that there's a spectrum: on one end tilled soil every season, and on the other end of the spectrum completely no-till beds where seeds are just sprinkled on top.
I usually fall in the 'little till' gray area, meaning that i work annual-bed areas by hand, shape them into raised beds, never walk on them. Sometimes I'll rotate crops by working it all by hand again, but more likely is just to take a small tool and scratch out seed/transplant holes wherever needed.
For perennials I may go straight to the 'transplant holes' step, never tilling the soil.
Maybe this gives more ideas. And it's a way of doing raised beds with native soil to see how to improve things.
To clarify what I'm trying to do, I'm doing independent study for school on veganic ecological gardening, and one of the questions I'm exploring is whether agriculture could be used to help restore land. I want to learn more about how to restore damaged and depleted soil so I'd like to be growing directly in the original soil and maybe adding to it as opposed to building on top of it. It sounds like I'll need to do some tilling, but maybe just do it once and avoid compacting the soil after that. Shaping into raised beds sounds like a real possibility.
There are many ways to till the soil, including "no-till" gardening. Really what no-till means is letting the worms do the tilling for you. By feeding worms, you encourage them to spend time there, eating their way through the soil, constantly cycling nutrients from top to bottom, as well as creating water and air channels to feed all of the other critters. The benefit of no-till is that, as stated earlier, you are not exposing the carbonaceous materials (which, in all their stages of life and decomposition are what make soil different from dirt) to the atmosphere, nor are you breaking up micro-ecospheres that the bacteria and fungi set up for themselves. If this is just for a report, you may look into the soil building practices of Masanobu Fukuoka, Yeomann (who is the man that Mollison got a lot of his ideas from), and Joel Salatin, among others. They all have a lot to say about improving damaged soil through agriculture.
If you're starting a garden, I like to fluff the soil (without turning it over, mind you) with a spading fork. Depending on the compaction of the soil, and a couple of days after a good rain, stick the tines of the fork in about 3 inches vertically, pull the handle back and watch the soil come up - don't rip the soil or invert it. Go back to vertical, put the fork in another few inches, and repeat, go back to vertical, this time put the fork in all the way (if the soil is really packed, you may not be able to do this all at once) and repeat. By the time your done, you should have increased the height of the soil by a couple of inches. Do it for an entire bed, which doesn't take nearly as long as it sounds, and cover with mulch. If you're converting lawn, put down a sheet of newspaper 4 pages thick or some cardboard, then cover with a few inches of grass clippings, horse manure, straw, etc. Never step there again. You should see a major increase in the tilth (dark, crumbly, earth-iness of soil) with a couple of months. I used this technique on a bed of river silt in New Orleans once, with very little humus to start. Within a year, the soil was black to about 5 inches. I consider it no till, maybe some would argue with me.
Check ATTRA for a thing caled strip tilling. This is much less invasive than regular tilling where all the soil is stripped of any plant life and tilled under leaving bare soil exposed. Strip tilling is usually done with a disc so a very small strip is opened just enough to put a seed there. Leaving all remaining ground covered. Big organic farms near where I live do this. Also check out roller crimping. A large roller with angle iron welded to it is used to roll over the weeds crimping them which makes them die back. This creates a green mulch over the surface and then the disc is run thru to cut a small row where seeds are planted. This keeps down weeds. Helps retain moisture, and doesnt till, and the green mulch breaks down int good organic soil.
I live in western Washington. My soil test indicates that my soil is fairly high in organic material, but low in nitrogen, calcium, magnesium, potassium and sulfur and has a low pH. Now, it sounds like a good idea to just sprinkle some dolomite lime, composted manures and maybe some rock dust, cover it with leaves and let it sit.
And that's just not going to do it. That lime needs to be incorporated into the top six inches or so of soil. Even then, that lime will take a minimum of three years to break down into a usable form. Letting it sit on the surface of the soil and hoping the earthworms will till it under doesn't seem very realistic.
Even Bill Mollison said he was okay with initial tilling.
And I think the term 'initial tilling' is the important thing here. Get your soil tested, decide what and how much you need of various amendments, spread it out as evenly as you can, and till it all in at once. If funds are limited, buy smaller amounts of each and do a section at a time.
Then, immediately afterward would seem like a good time to plant a cover crop or cover crop mix. Choosing what kind(s) would be best for your soil would probably take some consideration and care. Maybe one that was planted late and would winter-kill and lay down and protect the soil would be a good choice. If you needed a lot of nitrogen and organic matter, maybe something like clover would be better, and till or disc it into the soil in spring. Or something like rye that might be alleopathic enough to keep the weeds at bay until it broke down and you could plant something else.
If you didn't need much organic matter but did need nitrogen, and you were just working a small plot at a time, maybe scattering some alfalfa meal or cottonseed meal and working it in with hand tools would be more appropriate.
Once you've improved your soil, and have found sources of mulch, start your no-till operation at that point.
If a person lives in an area that has a lot of deciduous trees and can just go down a few streets and pick up 200 bags of leaves, that's wonderful. I live in an area of Douglas fir and oaks. I'll have to find a different way.
The thing is, there isn't likely to be one single way to handle all situations.
Fit your plans to your needs, don't try to force an inappropriate method/materials where it won't fit.
And keep in mind that what many farmers refer to as 'no-till' is really 'no-till with lots of herbicides'.
The way I understand it, the trouble with that is the lime doesn't really move in the soil, like nitrogen or other things do. I don't think doing it lightly several times would be any advantage.
Last Fall, I spread 10 bags of lime on a strip about 30x300'. It never got tilled in, so I just shrugged and thought, "Well, let's see if it makes any difference that way", and marked the perimeter with a few stakes. Since I had unlimed soil right beside it, I thought I would be able to see some difference if there was any. None at all, that I could see. The limed area has the same varieties of (acid-preferring) weeds that the unlimed part has. Now, maybe it will have to take the full three years to show difference, but that's THREE WHOLE YEARS!
I understand that nitrogen will off-gas into the air, but I have so little (3 ppm) that I don't know that it would make much difference. I think the acidity and lack of calcium/magnesium may be slowing down the breakdown of the OM (15.6%, IF I took the samples correctly) into nitrogen. I am thinking (possibly erroneously) that if I add the lime this fall and till it in, and maybe add a bit of alfalfa meal to add more nitrogen (and it's a bio-activator, too), and top it off immediately with some mulch, maybe that whole patch will sort of break down together, without losing too much good stuff, and also without wasting too much more time.
According to agronomist Neal Kinsey, if you add, say, 40 lbs of dolomite lime to 1,000 sqft of soil and mix it in during the Fall, only about a third of the calcium and magnesium will break down between then and the next Fall and become part of the colloidal complex, where the plants can use it and the benefits it provides. Another third will break down during the second year, and the last third will break down during the third year. And that's only if the lime was finely ground; if it was in a coarse form, he says it can take up to ten years to actually become part of the soil.
Some will wash into the soil. Some will be carried into the soil by earthworms and other little beasties. It is slow. It also depends on a lot of factors. On "dirt", there won't be much in the way of little beasties, and pH/calcium might be the least of your worries.
If you are growing something acid loving, and you throw down lime, well, it probably won't help.
you can open up the soil for the plant roots without tilling it.. For larger areas you can chisel plow which created grooves in the soil, for the roots and water to use..or if it is a smaller area you can use a fork..stick the fork tines into the soil, stand on it and wiggle it back and forth, this creates small holes in the soil but doesnt'n turn it or compact it..but loosens it and makes it better for planting..
see the other "till" thread on this forum for more info
Bloom where you are planted.