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!! To Till, or Not to Till, and WHY  RSS feed

 
Tom Turner
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I'd like to hear the reasons why hashed out, not just the opinion of experts or any claim to settled science. To rid the question of some baggage I'd like to set the premises, but feel free to amend these premises:

<> The decision to cultivate perennials demands No-Till. The decision to cultivate a mixture of perennials and annuals on the same piece of ground also demands No-Till. So the question must really be focused on the cultivation of annuals -OR- strictly for the creation of the soil itself (such as turning in a cover crop). 

<> Assume that both Till and No-Till seek to build fertile soil and both wish to invest (e.g. organic matter or non-productive fallow time) in building that soil.

<> Assumptions which should not be made is that tilling is done as a stand-alone practice and by necessity leaves the soil uncovered (which is the image most have of modern industrialized farming practices).


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Travis Johnson
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My farm has an issue with how easily the soil becomes compacted, so as much as we would like to go with no-till farming, we just can't. But just because we do, does not mean that we are abusive either, we do something called Minimum Till which for us is a great middle ground between the extremes. It really has cut our fuel consumption down, yet allowed us to grow quality and abundant crops too, so we are happy with the results.
 
Tom Turner
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I hope I'm not out-of-line by copying this from the other thread Building soil and repairing compacted land, but it is a direct argument from Marco Banks for No-Till. Link Here


Yes, the initial till "lightens" the soil by introducing a lot of air into the soil profile.  But it's an unnatural way of pushing that air into the soil, and it quickly compresses back to an even more compacted state because there is nothing present that holds the soil structure open.  Further, all that extra oxygen artificially pumps up the microbial activity, which in turn eats up the soil carbon.  Within a couple of months, you've burned through the soil carbon, leaving just mineral soil --- and that compresses like a punctured basketball.

Soil aggregation and aggregate stability are not a result of mechanical processes (running a plow through the soil) but chemical and biological processes.  Well-aggregated soils are crumbly and “open”, allowing water to easily infiltrate rather than run off during heavy rain events.  They will have the texture of cottage cheese. The exudates produced by plant roots are the glue that binds soil into the crumbly texture.  Root surface fungi also produce aggregate glues, further enhancing aggregate stability.   Without these glues, no amount of tillage will permanently "lighten" the soil because it all goes back to an even tighter formation.

The name of these fungal glues is glomalin—a chemical produced by Mycorrhizal fungi that increases microporosity (creating empty space within soil for water and air to flow through).  Glomalin hangs around for about six months after the root dies and the fungi are no longer present.  But it eventually breaks down, and the soil aggregates turn to powder.  Every time you till, you rip those fungi to pieces, and thus hinder the production of glomalin.  If you want your soil to remain aggregated, you've got to have a continual supply of glomalin being pumped into the soil ---- a living root with attached fungi, preferably, 12 months a year.

So I'd argue that its best to never till --- even the first time.  If you can establish a cover crop without tilling, you'll be much better in the long run.  If you can innoculate your cover crop seed with a fungal starter, all the better.  But even if you don't, there are enough fungal spores floating around out there (and already present in your soil), fungi will eventually colonize your soil.

Best of luck.


Here's a link that talks about soil aggregation.

https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052820.pdf


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Todd Parr
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I'm from a different camp than Marco on this issue.  I personally don't till because I'm not in a big hurry, but I see nothing  wrong with tilling initially to create a garden space more quickly.  I use large pieces of black rubber roofing material to kill off everything in a given area before planting it or putting down wood chips or whatever I'm going to do with it.  This can take a year or more just to initially kill everything off.  I can't believe that tilling an area once is any more harmful to it than my method is, and my land bounces back surprising quickly.  If I were going to do it over again, I would till my planting areas, pick out as much quack grass as I could, wait a couple weeks, till again and pick out the chucks of quack grass, till in a bunch of compost, chicken bedding, manure, whatever, and then plant cover crop immediately or cover with wood chips and plant.

I think you also need to explore the difference in tilling methods.  Plowing is not the same as rototilling, is not the same as double digging, is not the same as ...
 
Tom Turner
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Marcos,

Interesting, both your post and the USDA article. I now understand soil aggregation as a sort of binding together tiny particles of, primarily, clay to form larger particles more like sand. It is analogous to making tiny bricks and this certain chemical, glomalin, that living roots infuse is the glue that holds these tiny bricks together. This ruble of tiny bricks (think artificial sand) give the soil porous pathways for the infiltration, and draining of, air and water. It also fortifies the soil against erosion, both wind and water. 

But the USDA tells us that sandy soils and soils with much organic material do not need aggregation, that there are three paths to porous and stable soil: Aggregation, sand and organic material. The USDA's target audience is the professional farmer and for him the decision to facilitate aggregation by simply not tilling is an attractive low-cost option.  But that doesn't also mean that the small sustainable farmer should not choose instead to promote soil porosity and stability through organic material in the soil.  And for the simple-minded small sustainable farmer (like myself) it seems like common sense to put the organic material IN the soil, not ON the soil.

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Todd Parr
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Tom Turner wrote:
But that doesn't also mean that the small sustainable farmer should not choose instead to promote soil porosity and stability through organic material in the soil.  And for the simple-minded small sustainable farmer (like myself) it seems like common sense to put the organic material IN the soil, not ON the soil.


It isn't an either/or proposition.  If you put organic matter ON the soil, rain, soil life and plant life will put it IN the soil.  Tilling after initially establishing an area causes problems because it kills soil life and disrupts the balance that nature creates.  It makes sense to me that soil life moves to the depth it needs to be at, to the root zone it needs to be at, to the temperatures that serve it best.  If you till, it destroys all that, and it has to start over.  You also bring weeds seeds up that were previously too far into the soil to sprout, and create an area of hardpan beneath your tilling depth. 
 
James Freyr
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This is a fantastic question, and there are multitudes of reasons why to and why not to. I will try to help (or further confuse) with a few reasons for both that I can think of off the top of my head. I'd like to start with reasons not to, and try to expound a little further on the text copied by Tom. Glomalin is very important to soil tilth and health and tilling also tears apart the long thread like fungal hyphae, which can take a long time to build. Certain soil bacteria can reproduce in lineal strings kinda like holding hands in long chains and tilling breaks these chains. Tilling can, depending on depth, bring anaerobic microbes from down deep and expose them to oxygen while simultaneously placing aerobic microbes near the surface down too deep where there is little or no oxygen, disrupting the balance of the microbes in place that have been residing in their preferred happy horizons. Tilling generally incorporates tons of oxygen into the soil, temporarily boosting aerobic microbe activity, which can rapidly deplete useable forms of nitrogen in the soil as the microbes chow down on carbon. When mechanical tilling disrupts the microbial balance, the ability for ion (potassium, calcium, magnesium etc.) exchange in the soil can come to a standstill until the microbes start rebuilding. Plants need the microbes to use the ions bound to soil particles. The preceding paragraph is basically a super brief summary of what's going on during and after tilling, but there's so much more and it can get complicated.

Reasons to till, and as Todd mentioned, there are many different methods to till. Perhaps you have earth that has been abused by 50 years of regular plowing and chemical fertilizer application. Tilling one more time won't make anything any worse, and one can apply large amounts of organic matter like a quality finished compost to the surface for example, and then till that into the earth, starting the process of building your soil, which can be followed by one or a combination of a variety of cover crops, to be either be chopped and dropped in place or, tilled under using it as a green manure. Working the fresh cover crops into the soil sequesters more carbon and puts the nitrogen back into the soil. Left on the surface, most of the nitrogen and carbon can go back to the atmosphere. Another reason from another unideal scenario: perhaps the land has been plowed repeatedly over the years with a moldboard plow and a hardpan has developed at the depth of the plow. Sometimes sub-soiling or chiseling can be warranted to break up the pan so water drains. Again, there are more reasons to till in different ways if it's warranted. I de believe it is generally understood that high speed roto-tilling does the most damage, with techniques like double digging or using a broad fork to be much less destructive.

Then, like Travis mentioned, sometimes you use the techniques that work for you to grow crops. Not all tilling is bad or completely destroys soil. One thing I've learned from books, magazines, my own trials, and from all the good folks on permies who grow crops all around the world, is that there is no one right way to grow crops. Travis has found that minimum till achieves the results he needs to grow good crops. I live in an area that is seemingly perpetually wet with clay like soil, so I garden in raised beds in order to get results and grow good crops. I really hope Mr. Bryant Redhawk chimes in on this matter, as he is educated in the science of soil and I bet he will have interesting things to say in regards to the question of till or no-till. I certainly hope this has helped.
 
Bryant RedHawk
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This is indeed an excellent question and I am sure it will bring out pro tillage and pro no tillage sides.

I think the first thing to understand is what tillage is and what it is not. 

Tillage = disturbance of the soil, this can be superficial ie. shallow disturbance as you get with a hand held power tiller, or it can be deep disturbance (subsoiler, deep tine plow, etc.).

No Till = no disturbance of soil except by seed drilling.

Tillage is normally thought of in the sense of the commercial farmer who constantly disturbs the soil to keep succession from occurring.

Now there are times to use disturbance, not in the normal "till the field" way but to replicate a natural disturbance to manage succession instead of wipe out succession.

Say we find a piece of land that is covered in canopy producing trees, of ripe old age under which no sunlight can penetrate, and we want to be able to grow foods on this land for our family to eat.
Or it could be a piece of land that has been in commercial farm use for decades and just acquired by you, who wants to convert it to permaculture methods.
In both cases it is impractical to leave the land as it is, on the first type there is no sun reaching the soil, on the second type there are no microorganisms in the dirt, only artificial nutrient levels.
How to make these pieces of land usable by us for growing good tasting, nutrient rich foods?
In the first case, we need to thin the canopy, that means cutting down trees, we might also chip up those tree left overs for use as mulches. Instead of cutting the trees down, we might opt to push them over, thus replicating wind blow downs, this disturbs the soil where the roots were (a form of tillage) exposing deep soil and mixing the horizons. This is how nature usually mixes soil layers.
In the second case, tillage can be used initially to disturb the soil, inoculate it with microbe rich compost, mixing this compost with the dirt thus creating a new microbiome that is rich in both bacteria and fungi, the two building blocks of real soil.

Note, neither case needs to be disturbed continually, only on occasion when nutrient levels or succession is about to go where we don't want it to go.

If you have undisturbed soil that has all the nutrients needed, then there is no need to disturb what is there, unless succession needs to be changed.

If you have soil that has been going through constant disturbance then you may need to disturb it once to replenish the life that was disked away by the previous owner.

I don't think there are many instances where there is only one way to do something. Nature uses lots of different ways to get succession either going or changed.
I do think observation, understanding the land before any actions are taken is the prime tenant everyone should heed and follow.

Redhawk
 
Joseph Lofthouse
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I love tilling perennial beds. It's a great way of incorporating organic matter into the soil and of minimizing annual weeds and some grasses. I till my raspberry patch under in the fall (only works with fall bearing raspberries).  I till asparagus, sunroots, chives, Egyptian onions, mints, etc... The perennials come back just fine after tilling.  I rejuvenate the strawberry patch by tilling.

 
Bryant RedHawk
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In your case kola, you are keeping the succession from proceeding, a perfectly good practice and different from the "till everything away and start over, annual crops only" farmer method most people think of first.

Redhawk
 
Travis Johnson
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One interesting thing that has always been done on my farm is; application of solid and liquid manure. Because of this, the organic matter is actually on the high end of the spectrum, and yes you can have too much! With my gravelly loam type of soil, water moving through the soil is not an issue. neither is soil fertility, but I base that on the organic matter. We literally are putting tons of compost on our fields per year, just as the Comprehensive Nutrient Management Plan says too.

Tillage is like saying something is metal though: and while aluminum has far different properties than cast iron, both are indeed "metals". So it is with tillage. We seldom plow here, and when we do it is merely to cut the sod for converting fields, like grass ground into corn, which we typically do every 7 years or so. Even then a farmer can "drop the plow" or raise it up and just cut the sod. The USDA says to "just cut the sod", but I like to go down to full plow depth which is 14 inches. Again that is only when converting grass ground back to corn (obviously with corn plowing is not required since there is no sod). But when in corn every year, we also subsoil which breaks up compaction deep down. But as long as the ground was corn the year before, we just hit it a few times with the disc harrow. This is minimal till, but or planter is designed for minimal till, which means it is designed to bounce off rocks basketball sized or smaller, which is still a pretty big rock.

The biggest reason for tillage here is incorporation of nitrogen. The faster you can get nitrogen (liquid and dairy cow manure) on the fields and get it into the ground, the less nitrogen that is lost to the atmosphere. We get some from the winter rye cover crops, but if we are all honest here, it is not nearly enough. It is a little different with the grass ground because the alfalfa mix helps with the nitrogen fixation with their deeper roots and larger plant size, but grass ground still needs a kick of nitrogen to get it to grow.

And the other reason is our acidic PH levels. This is Maine, and due to the topography, our position East of everyone else in the USA, the coal fired power plants in the midwest, the jet-stream, etc...we experience high amounts of acid rain. Our wetlands are saturated and can no longer filter this out. So we have VERY acidic soil...5.8 in PH levels. To get crops to grow it needs to be neutralized, but that takes lime. Unfortunately our lime quarry stopped selling agriculture lime, in bulk or in bags, so now it must imported from Canada, and it is EXPENSIVE. So we use a natural product called AlgeaFiber which is seaweed! It is awesome stuff, better than lime because it has micro-minerals in it, however it takes A LOT. It takes 10 tons of AlgeaFiber to equate to 1 ton of lime, but you cannot spread that much lime on any ground and not till it in. No way, no how, it would be smothered. So we put it on the corn ground only and till. Minimal till, but tillage.
 
Marco Banks
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Tillage is hell on fungal networks.  When you run a plow/disk through soil, those long threads of mycorrhizal fungi hyphae are chopped to pieces.

I never used to believe this, but the more I read, and the less I till, the more I see evidence of an ever-growing fungal network (mushrooms popping up all over after a big rain).

For that reason alone, I've stopped tilling.  The soil is better than ever --- friable, light, black, and well aggregated.  Because of the mycorrhizal fungi, it's more fertile than ever before.
 
Travis Johnson
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Marco the interesting thing is that we have the same thing here, friable, light, black, and well aggregated soil, but we do till. I do not doubt that tillage disturbs the long threads of mycorrhizal fungi hyphae, but wonder if where we fortify the soil with so much compost that it does thrive? Mushrooms are not so much an indicator here, but earth worms sure are. They are huge indicators that my soil has ample amounts of organic matter and vitality, and the birds here know when we plow; the soil is crawling with worms.

I have even watched videos of Gabe Brown's farm and see where our results are similar to his. This is not really surprising. He lives in a location where synthetic fertilizers are always used, where as he uses his animals to graze and spread manure over his ground. To break up compaction he uses turnip to drive root stock deep then decompose. We actually are doing the same thing, but rather then use animals grazing over the corn ground obviously, we use mechanical means to spread manure and mechanization to break up compaction.

In my line of thinking, why you and I are getting the same results is; where as you are not disturbing the mycorrhizal fungi hyphae by not tilling, my farm is providing so many nutrients to them that they are thriving in the year between tilling. Neither is right or wrong, just different ways of achieving the same thing.

Having cleared a lot of forest back into field, I have tried no-tilling the first few crops; both corn and grass. I was rather surprised with the lack of growth. I though the roots of the trees (mature forest) would break up the compaction enough to save me tillage costs. This has never worked out. One was a 10 acre corn plot, and the other a 12 acre plot planted to grass. I did end up deep tilling (plowing) and subsoiling the corn field and eventually got it to really grow, but the grass field is still languishing. I do think some of that has to do with nitrogen fixation, and robbing of the soil; as this was mature forest, but the recommendations were unique. First try 100 pounds of fertilizer to the acre, and if that does not work, rip it open and try reseeding.
 
Maureen Atsali
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I hope there will be more replies to this topic.  I am very interested to hear more view points, and I appreciate those who shared already.

I am no expert, I can only share what has and has not worked.  I like all the science behind no till, and I have tried it, but it hasn't worked for me here on an extremely degraded former sugarcane plantation in the tropics with acidic clay dirt.  I couldn't grow enough to feed my family, and we were too hungry to wait years.

Now we plow, by hand with a hoe like tool called a jembe.  After plowing there is a nasty invasive grass root that has to be pulled out by hand, or it chokes out everything.  Then we plant and mulch.  But weeds are so aggressive, and mulch materials are so limited, and mulch breaks down so fast, that everything has to be weeded at least once.  If its a fairly new, unimproved place, that means disturbing the soil again, to get those roots.  (It takes about three years of continual removal before this step is no longer necessary.). In places we have been working for many years, we can pull weeds by hand without digging.  Then we mulch again.  Many of our crops are underground annuals, and so the soil is disturbed again at harvest.  Ground nuts, sweet potatoes, casavaa, taro, etc.

While all this disturbance surely isn't good for the soil biome, it has enabled us to get a crop from soil that was completely dead, or missing due to erosion.  Soil is improving every season, and so is the yield.  I assume that is mostly due to the mulch, which spends the growing season on top, and then gets plowed under in the next season.  Manures and compost are also spread on when they are available.  Also I think the rotations and variety of plants we grow, which includes a lot of nitrogen fixers is helping.

It may not be a perfect system, but it is getting us the desired results.

By the side..  This thread started by saying you couldn't mix perennials and annuals AND till.  But I do, and its possible because we are hand plowing.  Its a simple thing to plow around the perennials. 
 
Marco Banks
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Adding so much wonderful organic matter to your soil clearly has made it healthy and full of life.  It takes a bit more work on your part, but it makes the soil very healthy.  I certainly have experienced that myself.  But the volume of compost needed to continue to feed such a system on any kind of scale quickly out paces the available supply.  Even with a healthy composting system, I don't have enough compost to go around, and that's even after I've dumped hundreds of yards of wood chips all throughout my system.

So as you mention Gabe Brown -- he farms hundreds and hundreds of acres but uses no such inputs as you or I do.  He's not making compost on that level --- and even his cows aren't doing it to the scale that we are.  He leans heavily on naturally occurring fungi to make his soil fertile and friable.  You and I can bring in these amendments (chips, compost, etc.) but you could never do that on a large-scale commercial operation like Gabe runs.  That's why he's 100% no-till.

I'm getting older, and with that, I'm certainly getting lazier.  I hope I'm also getting wiser.  Could I increase my production if I were able to find a way to significantly increase the volume of compost I were able to add to my soil?  Absolutely.  But I don't have the time or energy to do that.  It stands to reason (in my humble opinion) that if tillage exponentially "blooms" the microbial life of the soil to burn through all the wonderful soil organic matter (SOM) that gets added, it's a vicious cycle to work so hard to make compost, only to till it in to feed an artificially stimulated microbial herd.  I'd rather take the slow route of creating a virtuous cycle (as you would find in a forest) where the soil food web self feeds, but never over-feeds.  That seems to me to be much more sustainable (certainly for my back and for the fossil fuels I will not be burning to gather up all those extra compost ingredients).

Permaculture is a design system predicated on mimicking natural systems.  Forests or savanna systems don't till, yet the soil is fertile and self-sustaining.  That's what I'm shooting for.

 
Tom Turner
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This is good because it exposes for me my ignorance of soil biochemistry. I've learned about: Soil stratafication of the soil biome species; the soil aggregating glue in living roots; and long strand fungi which tilling kills, disturbs, destroys... I don't know what the right word is but it does pose for me the obvious questions; What is the tillage-kill (like "winter-kill") percentage? And probably more importantly: What is the recovery rate from tillage-kill? In my mind I imagine that the same awesome explosion of above ground life that we experience in the spring also happens below ground. But I am just emoting and the actual science of it often destroys such warm-n-fuzzy emotions.

~

I may be be under the influence of popular myths but here are two things I have heard: When Europeans came to the North American prairie they found 3ft or more of rich topsoil. That seems like proof of a No-Till paradise. (When I think of how in such a short time we, with our plows, have exposed that treasure to erosion and flushed it all into the gulf of Mexico I naturally emote and tend towards being viscerally anti-plow. I also wonder about the overall productivity of putting a steak on the table - nature's system of free range buffalo fed on no-till grasslands vs man's system of ammonia-fed corn and corn fed cattle)

The other example is the South American rain forests which, blessed with sunshine and moisture has (or had) a massive abundance of biomass yet has proven to have extremely shallow soil depth. If it were the root structures, bacteria and fungi which created the awesome soil of the North American prairie paradise, why did they fail so miserably in the South American rain forests? Redcloud uses an old growth forest as an example and I can see how it would kind of isolate the topsoil from sunshine and soil creating shallow root systems. The old growth trees dominate the very high (canopy) and the very low (deep roots) and the middle where the top soil is, is kept stagnant. And yet it is rich with leaf litter compost food for our beloved bacterial minions. But the rain forests have abundant undergrowth, one needs a machete to get through it. So too does the new-growth forests of North America have abundant undergrowth; dense root systems and copious leaf litter, and yet create topsoil very slowly. The popular myth is that woodlands create topsoil at the rate of 1 inch per century (?).

Can anyone explain that seeming conundrum?

.
 
Tom Turner
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Marco Banks wrote:Adding so much wonderful organic matter to your soil clearly has made it healthy and full of life.  It takes a bit more work on your part, but it makes the soil very healthy.  I certainly have experienced that myself.  But the volume of compost needed to continue to feed such a system on any kind of scale quickly out paces the available supply.  Even with a healthy composting system, I don't have enough compost to go around, and that's even after I've dumped hundreds of yards of wood chips all throughout my system.

So as you mention Gabe Brown -- he farms hundreds and hundreds of acres but uses no such inputs as you or I do.  He's not making compost on that level --- and even his cows aren't doing it to the scale that we are.  He leans heavily on naturally occurring fungi to make his soil fertile and friable.  You and I can bring in these amendments (chips, compost, etc.) but you could never do that on a large-scale commercial operation like Gabe runs.  That's why he's 100% no-till.

I'm getting older, and with that, I'm certainly getting lazier.  I hope I'm also getting wiser.  Could I increase my production if I were able to find a way to significantly increase the volume of compost I were able to add to my soil?  Absolutely.  But I don't have the time or energy to do that.  It stands to reason (in my humble opinion) that if tillage exponentially "blooms" the microbial life of the soil to burn through all the wonderful soil organic matter (SOM) that gets added, it's a vicious cycle to work so hard to make compost, only to till it in to feed an artificially stimulated microbial herd.  I'd rather take the slow route of creating a virtuous cycle (as you would find in a forest) where the soil food web self feeds, but never over-feeds.  That seems to me to be much more sustainable (certainly for my back and for the fossil fuels I will not be burning to gather up all those extra compost ingredients).

Permaculture is a design system predicated on mimicking natural systems.  Forests or savanna systems don't till, yet the soil is fertile and self-sustaining.  That's what I'm shooting for.


You bring out another valid critique against tilling. If tilling is for the purpose of incorporating much organic material into the soil it is essentially a system of concentrating biomass from a large area to a smaller area. Do we adopt a system where there is a uniformity of bio-density (did I just invent a word?) across thousands of miles of farm land? Or do we have many smaller discreet points of extremely high bio-density amidst a relative dearth of bio-density? If we move towards greenhouse agricultural production or a more widespread use of home gardening where everybody has a "victory garden" the latter makes more sense.

.
 
Marco Banks
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Tom Turner wrote:


The other example is the South American rain forests which, blessed with sunshine and moisture has (or had) a massive abundance of biomass yet has proven to have extremely shallow soil depth.

The popular myth is that woodlands create topsoil at the rate of 1 inch per century (?).

Can anyone explain that seeming conundrum?

.


There are a couple of variables at play.

1.  Warm, wet ecosystems provide an ideal climate for bacteria growth.  So while you have a massive amount of bio-mass being produced in the Amazon rain forest, you have an equally active bacterial community that is eating it up as soon as it falls to the forest floor.  It doesn't take long for a dead tree to "gas-off" (that is, much of the mass turning back into carbon dioxide as decomposition occurs).  In the same way that a compost pile heats up and "cooks down" because of a microbial bloom taking place in ideally created conditions, much of the bio-mass produced by the rainforest is quickly consumed by the abundant micro-herd. 

If you were to transport that same fallen tree to Arizona and drop it out in the desert, it would sit there.  And sit there.  S   L  0  W  L  Y decomposing.  For years.

2.  Temperate ecosystems (like we have in North America and Europe) have a winter kill, where shallow rooted perennial plants are frozen and the cell walls of the plants are burst as they freeze and thaw a couple dozen times over the course of the winter months.  No such freeze/thaw cycle occurs in the heart of the Amazon.  So?  What's the big deal?  Well, in healthy savannah grasslands (like much of America was at one time), this annual kill did a couple of things.  The tops of the plants were killed and dropped to the soil surface to feed the surface biome -- worms, dozens of different kinds of beetles, seed-eating birds and critters, etc.  The roots of these grasses and forbs also died, but did not decompose so quickly.  S L O W decomposition allows more of the biomass to turn into the black jelly-like humus that is resistant to further decomposition.  Yes, those roots rotted underground, but at a much slower rate than the bio-mass on the soil surface.  The lack of oxygen has a lot to do with that.  So SOM builds up, ever so slowly, but often reaching a stasis of 5 to 8% (give or take, depending on the biome).

The annual freeze/thaw and wet/dry pulse makes a huge difference, compared to the consistent warm, moist conditions that you have in tropical regions.

3.  You mentioned the massive trees found in the tropical rainforest.  The established tree canopy eliminates light to the understory.  I'm working my way through the recently published (in English, from German) "The Secret Life of Trees" by Peter Wohlleben.  He talks a lot about the massive beech trees in the old growth forest he manages in German.  These ancient trees live 800 to 1000 years.  Can you imagine how many millions of seeds a 1000 year old tree will produce in its lifetime?  And how many trees will ultimately replace that ancient tree over the next couple of hundred years?  One.  Stable forest systems reach a point of stasis where, out of the thousands and thousands of seeds that sprout and grow, only one tree will ultimately reach full maturity over the following centuries.

In grass-lands, the annual lifecycle of plants allows for one well-suited plant to give life to hundreds or even thousands of off-spring to carry its genetic imprint forward.

So?  Well, change and succession happen much quicker in a grass-land than in a forest, even as deep rooted grasses pump the soil with exudates and fungi feeding sugars and starches (cookies and cakes, and Elaine Inghan likes to call them).

Ruminants eat the top of the plant (another pulse in the system) causing the grass to sluff-off roots.  We call this maintaining the "root to shoot ratio".  So the many massive herd of a couple of million buffalo, constantly on the move because of wolves and the need for new fodder, walked across this country, eating grasses that may have been as tall at 10 feet or more, crapping their way across the land, and forcing those grasses to sluff-off excess roots.  Prairie grasses have roots that go 4, 5, 6 feet deep or more.  Buffalo or elk eat grass.  Grass sluffs-off roots.  Bio-mass is integrated deeply into the soil.  Top-soil is built.  As Joel Salatin if fond of saying, cows and other ruminants are the biological reset button for soil development.

No such ruminants, grasses and naturally occurring pulses are found in the Amazon.

Those are three reasons why the world isn't lopsided, with Brazil having 100 feet of topsoil.
 
Erwin Decoene
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On the till versus no till debate i tend to the no till side. That said i think i need to point out a few things.

- Natural soils loose nutrients. Nutrients leach out and mostly end up in the ocean. In some climates the leaching process is fast. In tropical soils humic acids, dissolved CO2 break down rocks extra fast and leach out lots of it. That's why it is a bad idea to cut down a tropical forest. Al the nutrients remaining in the ecosystem are locked in the biomass.
The leaching process is the reason why many tropical soils are redish or brown. Iron and aluminum compounds are among the most stable minerals in such a climate. That's why bauxite ore is usually formed (and found) in the tropics.
In temperate climates the leaching goes slower.
It follows that lots of biomass means one more way to retain nutrients in reach. One nutrient leaching out easily is potash/K/kalium. The only way to replenish it in the old days was to gather biomass where it was concentrated by a variety of premodern industrial activity (such as leather processing) OR by burning biomass. That's where the 'ash' in potash comes from.

One way nature rebalances this leaching process is by churning up the earth. Glaciers plowed the continental masses of the northern hemisphere for the last
2 million years, the loess deposits in Europe, America and Asia are so fertile because the glaciers ground up rocks and continental seabeds and mixed everything up. Another way is by spreading windblown volcanic dust and ash. Yet another one is by dust blown away from steppes and deserts.

Amazonia and Australia are areas of generally very poor soils due to long term leaching >> 10 million years.
The amazon basin gets some fresh nutrient input from fresh ground up rocks in the Andes, Andes volcanoes and dust blown over the Atlantic out of Africa. Australia gets some volcanic dust from Indonesian volcanoes.....
The environmental catastrophe in the Sahel may have enhanced the nutrient levels in Amazonia...

- Commercially farmed soils loose nutrients when the produce is removed from the local ecosystem, processed and shipped out. Food trade is basically (among other things) a trade in nutrients. A ton of corn produced in the US midwest with phosphate from Florida or Marocco and shipped to subsaharan Africa is not only food but also a transfer of soil nutrients.

- Tilled and overmanured soils loose nutrients to rivers and aquifers where the nutrients cause problems in ecosystems used to a lower exposure to nutrient concentrations. Overmanured soils are a problem. In Europe soy from Amazonia and elsewhere is used to feed cattle. The resulting manure is dumped on fields in quantities that many fields are now oversaturated in phosphates.

- In the days before guano imports and artificial fertilizers there was a fine balance between the acrage of hay land and acrage of fields. Nobles tried to keep control over hayland. Hayland was basically a leached nutrient capture scheme. Nutrients leaching out locally or elsewhere were brought back in a landbased ecosystem by irrigation and fiddling with the groudwater levels. Grasses and herbs were harvested, dried into hay and then fed to farm animals. The resulting manure was used in the fields.
That was in essence a transfer of minerals from riverwater, ground water and soil minerals in the hay field to the grain fields. So those who controlled the best hayfields were either the local big shots (mostly nobles) or rich farmers/gentry.

- Tilled soils are very vulnerable to erosion.

- In Belgium and the Netherlands there was a trade in all kinds of special composition waste since the middle ages. I suspect that was pretty much the case in the rest of Europe, China and Japan as well ('night soil'). Farmers in Belgium managed to build up fertillity using those inputs and specialised farming techniques in combination with tillage. So they did something correct.
Of course tilling the earth with a halve ton horse to a depth of 10 to 15 cm is something different doing it with a 5 to 15 ton tractor plowing to 30 cm or deeper.


For me the main advantages of no till farming is 1) in the erosion prevention 2) the reduced los of added nutrients 3) soil processes are more akin to the processes that build the original soil. That way we restart the formation of new fertile soil from barren dirt..... 4) fungi networks are kept intact.

I hope to go notill in my garden in a couple of years. First i want to dig out the building waste left there by previous owners of the property. I also want to improve the water balance in the garden. For now i'm digging - sometimes as deep as one meter. I'm really looking forward to an end of the digging.



 
Travis Johnson
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Gabe Brown is 100% no-till, and while I have watched a lot of his videos and is known to say that his system is transferable to anywhere in the world, that is not true. I say that because he is farming West of the Mississippi where acidic soil is not an issue. Never in any of the videos I have watched has he mentioned the problems of acidic soil. The two people who have posted about their farm requiring tillage being required...one in Maine and the other in tropics located around the world...have extremely acidic soil however. That is not a coincidence.

If I was only growing grass, PH levels would not be so much of an issue. Grass is a lot more tolerant then crops when it come to PH levels, but 5.8 is not just low, it is extremely low, and that locks up the nutrients from plant uptake in the soil. To get to optimum levels, that requires 8800 pounds per acre, 4.4 tons, and since we cannot obtain lime reasonable, we have to go with AlgeaFiber which is is a staggering 44 tons to the acre. Thankfully the majority of that product is perlyte and really lightens the soil, but even staggering the remedial levels over a few years time requires tilling that much material into the soil. That is just something Gabe Brown does not have to deal with...and why pioneers left New England for the mid west in the first place!

But all is not lost, with lots of dairy farms here, and long periods where winter feed is required, we have ample amounts of manure. How it is dispersed can be varied, but doing so mechanically we have very tight constraints on where and when it is placed. That is actually a HUGE plus because after the ground freezes any manure applied...whether on pasture or spread mechanically, is just going to run off and pollute waterways when the spring melt comes. There are laws against mechanically spreading, and we can control precisely the amount and location of where manure is spread.

Inevitably Gabe Brown is going to have an issue on his farm eventually, unless he does fallow ground that I am not aware of. It will take awhile to show up, but the problem is not science as much as math. A grazing ruminant poos 85% of what it eats back out which is a 15% deficiency. Add in that deficiency on the same given space and the soil will be depleted of its required nutrients in 6 growing seasons. Now ideally a farmer lets that field rest for the seventh year allowing the ground to grow up, winter kill, and then be regrazed the following years since it has had a chance to naturally rejuvenate. In the case of the mid-west prairie this often happened because the roaming animals did not graze 100% of the grass down, and inevitably they did not graze 100% of the same acres every year, so there was a lot of natural fallow ground. Now farming over 1000's of acres, it will take awhile for that deficiency to show up, but if every acre is in some sort of crop production, we as humans must make up for the loss nutrient wise. Today with property taxes being high, farms smaller in size, and every acre needed to make a profit, we need to provide for that nutrient loss to our cropped fields whether grazed, hayed or row cropped. I use fallow ground to do so, as well as crop rotation and inputs of manure.

 
Andreas Schäfer
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About one and a half year ago I moved from the Netherlands to Portugal, and started with permaculture on a one acre plot. Like in the Netherlands, tilling and plowing is very popular here. In Holland it seems to make sense, there are almost only big farmers left in Holland, they do monoculture on big square (and flat!) plots. Here in the hills there are only small fields, and slopes. I guess most farmers here have not so much land, but still they plow the land around their trees, or they use pesticides to kill off all weeds that compete for nutricients with the trees. My land was not used over the last ten years, but the previous owner kept plowing to keep the forest where it is, and to keep the brambles from taking over the whole. I see that a lot, they plow, but don't grow anything most of the time. They just leave the bare soil to the sun, rain and wind, on a slope.. In my opinion that is the best way to create a desert. Especially on slopes disturbing the soil creates a lot of erosion.

So my land is very compacted and not very fertile on most places, but I already see some progress! I have to wait another six months for my first compost, but I found a no dig method that works for me, but it takes time. I have three chickens and a rooster, and I use their waste, a mix from half decomposed greens they didn't eat, combined with their poop. Together with some woodash and charcoal and some woodsoil I put it on top of the soil, add some mulch and keep it wet. After a few weeks I don't see or smell any chickenmanure, and I start to plant into it. On some parts of the vegetable garden I already have some fine black rich topsoil, just in a few months! So it works fast, but the material is limited.

It has been very dry here the last few months, usually this should be the time of the year the rain should fall to get us through a always dry and hot summer. Grasses are yellow already, so nice mulch is not easy to find. But I have patience, and piece by piece I will continue with my no dig garden, and hopefully in a few more years I can show the local farmers that crazy foreign guy might be not that crazy!
 
Tom Turner
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Erwin Decoene wrote:... Nutrients leach out and mostly end up in the ocean. In some climates the leaching process is fast. In tropical soils humic acids, dissolved CO2 break down rocks extra fast and leach out lots of it. ...


Thanks for teaching me a few things. While I still disagree with the assumption that tillage equals erosion I appreciate the rest of your post. Let me ask something on this one Issue: What is the stronger factor here: Excessive rain fall, or excessive humic acid/dissolved CO2?  Does the rain forest of the Pacific North West US have the same poverty of top soil? 

Either way without excessive rain fall the dissolved nutrients will not be flushed away and this whole issue seems quite simply a mechanical issue. Just as in areas with less than ideal water flow, such as Marcos' LA and nearby San Joaquin Valley, extra water must be brought in. In areas with excessive rainfall, such as the Amazon, excess water must be diverted away through canals back to the ocean without being allowed to percolate through the soil into the aquifer. Contrary to what Joni Mitchell sang, the Amazonian farmer really does need to Pave Paradise and Put up a Parking Lot.  No?

.
 
Tom Turner
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Marco Banks wrote:
There are a couple of variables at play.

1.  Warm, wet ecosystems provide an ideal climate for ... (above ground) active bacterial community ...

2.  ... S L O W decomposition ... underground ...

3. ... In grass-lands ... Ruminants eat the top of the plant ... causing the grass to sluff-off roots.  We call this maintaining the "root to shoot ratio".  Prairie grasses have roots that go 4, 5, 6 feet deep or more.  Buffalo or elk eat grass.  Grass sluffs-off roots.  Bio-mass is integrated deeply into the soil.  Top-soil is built. 


I hope I haven't lost the ideas with my summarizing of these variables.

In the No-Till system extra organic material is added above ground and that is where the decomposition happens. The freed nutrients of decomposition is then carried by water down into the soil. (Do I have that wrong?) So I read your points 1 and 2 as arguments against adding organic material on top, if organic materials are added they should be added into the soil. It seems the system you have in mind is laid out in point 3 - the only good way of introducing organic material into the soil is by living roots which die.


In the example of the No-Till Prairie paradise there is a chicken-n-egg paradox which you have adamantly chosen one side. Is there deep organic material because the roots grow deep (then die)? -or- Do the roots grow deep because there is good organic material down there? You choose the former. I'll champion the latter:

It is was NOT a No-Till paradise. It is was a Till paradise utilyzing nature's perfect tilling machine- The Ant! I've read that ants consumed many times more grass than any ruminants ever did. Ruminants, unless they poop directly into a prairie dog hole, are top-dressers (which you have just given us the arguments against). For a visual of the awesome performance of the ant-tiller (like "roto-tiller") see ant hill art. These diligent little workers burrow deep holes into the ground, yet still leave the biome intact. Then they set about a continual march of carrying huge burdens (for their size) of organic material down into the soil. After a life seemingly dedicated to soil amendment they then commit their body to the cause. Then the roots have found a new serendipitous teleos, a new goal in life to grow deep to grab the wonderful bounty provided by the heroic ant.

You are absolutely right that we should mimic nature's systems and what we need is a better mechanical system of inserting organic material into the ground without destroying degrading the biome. To work synergistically with nature.  It would not be difficult to create a machine which core-drills a deep hole and then immediately fills it with organic material like a thick slurry.

 
James Freyr
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I'd like to comment on tillage equaling erosion and it doesn't, but what tilling can do is make conditions right for erosion to happen wether the wind carries away a percentage of silt particles or rains wash away a percentage of particles, and some forms of tilling are worse offenders than others. I think it's also important to consider leaching and some elements are more apt to leaching than others. Anions like nitrogen in its available forms do not bind to soil particles and are mobile and therefore move with water and can go back to atmosphere, whereas calcium for example, a cation, is bound to soil colloids and it takes a little chemistry for it to be removed from its temporary home on the soil particle to become mobile and move with water. And of course if soil particles are washing away, it's taking the pantry of cations bound to the soil particles with it. Growing up my father would broadcast turf fertilizers several times annually to make the lawn a deep dark green, and knowing what I know now, looking back only a small percentage of that nitrogen was ever used by the turf or shrubs/trees in the yard and even without excessive rains, a good portion of it passed right on through the soil and subsoil polluting the watershed and water table.
 
Marco Banks
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This thread has been tremendously enlightening.  Thank you everyone for the contributions you've made.  I did not know so many of the things that have been mentioned (acidic soil, volcanic dust, etc.).

While I'm about 95% no till --- I just punch a hole in the ground to pop a potted pepper or tomato into the soil or I make a shallow furrow to plant seeds --- I'm not the least bit of a purist when it comes to bringing in mulch.  I mulch like there is no tomorrow.  My system is small enough (about a half-acre) that I can cover it with wood chips almost every year.  It takes 3 or 4 truck loads of fresh wood chips to do so.  I get then as I see them available, so there isn't a strict schedule as to when and where I mulch.  If someone is out on the street chipping tree branches, and if I'm able to convince him to dump them on my driveway, I'll be mulching the next available space.

So I'm totally pro-mulch.  I was doing Back to Eden years before that movie came out.  Paul G. validated pretty much everything I've experience in my own system.

I would argue that the mulch is just as critical to soil health as is minimizing soil disturbance.  Carbon feeds the soil food web.  Carbon feeds the fungal network.  Living roots in the soil and a carbon layer on top of the soil = soil decompaction and soil friability.

To loop back around to the OP, addressing decomption isn't just a one-variable question (to till or not to till). 

In regard to Gabe Browne's system running an annual deficit that will ultimately lead to a crash if he doesn't leave it fallow:  there is an assumption being made that it's a closed system where new nutrients are not coming in.  That's a false assumption.  There are several key naturally occurring inputs bringing nutrients into the system.

First, sunlight.  The entire soil food web is solar powered.  Photons hurtle through space for 14 minutes before landing on Gabe Brown's farm, being captured by one of a wide variety of plants waiting to collect it.  His farm has millions and millions of little solar panels, turning that sunlight into sugar/carbohydrates and carbon bio-mass.

Second, rain.  Rain events are nitrogen events.  Snow brings with it a tremendous amount of nitrogen.  If the soil web it healthy and carbon-filled, that N is captured and kept in the system.

Third, air.  70% of what we inhale with every breath is Nitrogen.  Plants, however, have a difficult time capturing that N, so they rely on fungi and bacteria working in symbiotic relationship with plant roots to fix nitrogen as well as mine the soil for other nutrients that the plants want.

Fourth, dust.  Nutrients blow in constantly.  Particularly when your neighbor is tilling his soil ---- all that dust has to blow somewhere.  Volcanic dust, dust storms in the deserts of far-flung places, etc. all put particulate matter into the air.  It eventually lands somewhere.  When you have a green crop growing on your soil 9 months of the year (even in cold Bismark ND), those wet morning leaves are dust magnets.

Fifth, ruminants, chickens, earthworms, birds, bugs . . . .    Organic matter (plants) grow simply from a seed, some rainfall, and the warm sun that sends those photons from deep space to our little blue-green planet.  No other inputs are required --- sun, water and some sort of mineral soil where they sink their roots.  But the magic happens when that organic matter moves through the digestive tract of an earthworm or Bessy the cow.  Biologic digestive processing CREATES nutrients that were not present in the food.   Did you know that there is 10 times more vitamin C in sourkraut than there is in raw cabbage?  Why?  Bacteria, fermentation, and some sort of biologic voodoo, apparently.  Dead grass goes into one end of the worm, and nutrient rich castings come out the backside, with all sort of complex waxes, emzymes, bacteria and fungi.  Millions of worms per acre are CREATING soil fertility just as fast as that growing sunflower plant can take it out.  In other words, the soil gets healthier from year to year, not depleted.

Sixth, fungi and freezing/weathering breaks down rocks.  Rocks are constantly being pushed-up from the subsoil to the upper soil profile where they weather and degrade.  A healthy fungal network will mine rocks to take from them the nutrients that trees and other plants want.  Crazy, huh? 

Seventh, plant bio-diversity.  Every plant brings its own chemical contribution to the party.  Trees are the ultimate dynamic accumulators.  They can live for 1000 years, pulling nutrition up from the deep soil and depositing that onto the soil surface annually when the leaves drop.  Gabe Brown talks about 50 or more naturally occurring species of plants in his pastures.  Each one of them brings a different set of chemicals and nutrients to the party.  Further, he's very intentional about planting a diverse cocktail of cover-crop seeds in with his cash crops (sunflowers, soybeans, wheat, whatever).  You might think of these cover-crop seeds as being an artificial input, and that would be fair, brought in as they are from the outside.  But you have to acknowledge that multi-species pastures and croplands BRING new nutrients to the soil profile --- they don't just take them out and use them up.

So, no, the system isn't closed with an annual drain of 15% of the fertility. 

Permaculture ISN'T sustainable.  Its REGENERATIVE.  I don't expect to lose any nutrients from my system as I eat my peaches and pick my corn.  I expect that next year, the peaches will be sweeter and the corn taller.  Between the chickens, the sunbeams, the raindrops, the fat poopy worms, me taking a piss on the compost pile, and the dandelions that create biomass for the birds and bugs to eat, the system gets richer with each passing year.
 
Erwin Decoene
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Some people here have argued here that tillage does not automatically mean erosion. Perhaps under some circumstances it does not but here in Europe there is lotst of scientific proof for the correlation. Tillage (unless by ants ) usually means that for a part of each year the vegetation cover is destroyed - creating optimum conditions for erosion. (In fact much of the modern erosion studies establishing the link were started in the US because of the dust bowl.)

The line of proof is something like this:

After the last ice-age a climax-vegetation formed constisting mostly of forest vegetation and some graslands. As soon as the climaxvegetation formed erosion rates plumeted. In many locations only lateral erosion of river banks provided some sediment to rivers. Of course leaching occured and perhaps even increased compared to the rates during the ice-age.

Later you see a drastic increase in erosion and sedimentation rates. That high rate of erosion persists till today and has reached something of a crescendo. If you look at a river basin with tillage agriculture today you see corresponding rates of erosion uphill and sedimention/sediment transport in the actual river and river plains. If you look at a vertical profile of river plains sediment you see fluctuations in the rate of sedimentation (= equivalent to erosion upstream) that seem to correspond to historical events. A drop in erosion/sedimentation (not to the level of the 'climax vegetation cover' time) in many places seems to correspond to the end of the Roman empire etc...
Now it is true that river sediment is sometimes hard to date accurately but the link is plausible. Locally there is very good evidence for the correlation.

In Iceland they have similar experiences. There the increase in erosion is more due to the degrading of vegetation cover by overgrazing after the colonization by the vikings.

I expect (but know of no scientific studies) that similar observations could be made in the river plains of North America.



As for the question what drives leaching most. I expect it to depend most of all on the amount of water percolating trough, the acidity of that water, the pH-buffering capacity of the soil and the temperature. Those variables will change from place to place and from season to season. I expect a well balanced soil life to be able to reduce leaching losses. After all that is usually the explantion given for the poor soils in parts of amazonia. Clay minerals and some volcanic minerals and organic matter can loosely bond nutrients so that the leached nutrients are not all lost from the local soil.

I don't know of the soils of the pacific northwest but i don't expect them to be extremely poor. The mountains there are basically pushed up seabed sediments. The marine minerals in those rocks will still have lots of nutrients locked into their cristal structure. Further there is volcanic activity there bringing up more nutrients.

The one nutrient that i would expect to be lacking most is probably nitrate. I saw a documentary about the role of salmon in boosting the productivity of the north american ecosystems.
Salmon brings N from the sea in the form of the proteines in its flesh. Salmon dies and is eaten. Bears and birds crap in the forest. Trees grow better/faster because of the nitrate boost.




 
Tom Turner
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Erwin Decoene wrote:Some people here have argued here that tillage does not automatically mean erosion. Perhaps under some circumstances it does not but here in Europe there is lotst of scientific proof for the (historical) correlation.


But lets learn from our mistakes and know that the way it all played out in the past is not necessarily the way it must play out in the future. Erosion is a mechanical problem. Tillage destroys the natural containment system of rooted plant life and ground cover. When man acts to alter nature by tilling they must also provide a new containment system. That is demanded by the new morality called permaculture. It is a mechanical problem but it is a moral issue. Here is a man-made containment system:

It's not perfect, but neither is nature's system of containment as evidenced in the formation of huge river deltas long before mankind ever invented the evil plow. Each particle of silt in the delta is the result of a failed containment system. I don't think the Filipinos built these containment systems out of moral concerns but of necessity to farm mountainous terrain. And I highly respect the ant-like diligence and hard work that the filipino displays here.

Here is another one which I prefer. Ironically it is not the result of trying to contain erosion but is the result of a massive social injustice called "the enclosure movement." It's containment purpose was to keep indiginous feral peasants (who previously were accustomed to "common land") off the land newly "owned" by the aristocracy and their friends.

I do not understand why this is not the agricultural standard around the world. It contains both water and wind erosion and provides a much needed place for a natural biodiversity of both flora and fauna. In New England the hedgerow system began by tilling which immediately uncovered massive numbers of field stones and frost heaves kept bringing new ones to the surface. So you drag them to the edge of the field. And you don't want to drag it too far, so fields were made small. An old time Frenchman moved down from Canada told me the optimum way was to build two large stone stone walls about 4 meters apart and then throw the smaller stones into that no-mans land between them. That no mans land becomes fertile because it catches the runoff nutrient laden leachate. It provides an immensely needed biodiversity and the trees needed continual trimming back which provided all the firewood needed. As an example, the raccoon population enjoyed the hedgerows and it became common practice to edge a corn field with two rows of corn then a row of marigolds (I think if memory serves me). The farmer back then just accepted his task was to feed the coons. Yet this hedgerow patchwork is a pain-in-the-ass for the tractor driver and it demands that a percentage of arable land be donated to the cause of sustainability. Two things that profit-driven agribusiness can not tolerate. See it's not really a mechanical or chemical issue, it is a social/political/economic issue. If each of those small fields were given to one of the progeny of those old time peasants who were originally kicked off the land and into a factory, then the tender loving care they would bestow upon their little patch of green would out-weigh any pros or cons of till vs no-till. But I don't think the land owning aristocracy would really like that.

If you walk through the woods of New England today you find numerous remnants of stone walls with some old trees in and around them. What once were the fields are all new growth forest and the size dates the time of abandonment to right around WWII. That's when the Eastern Farmer simply gave-up and got a job in a factory. The eastern farmer could not compete with new industrialized farming techniques which exploded in the West. I've done so many cross country trips on Interstate Highway 80 and it is incredulous that there exists very little in that probably 2000 mile field except corn and some soybean - one massive mono-culture field broken up only by the occasional roadway and brown river.

The other requirement is ground cover. Just as the No-Till advocate emotes at the horror, the carnage of a roto-tiller destroying the soil biome, I cringe at bare uncovered soil. And that includes the un-tilled soil which is becoming the norm across that 2000 mile corn belt. Yeah there is a little stump from the corn plant remaining but the vast majority of the soil is naked and loosing it's nitrogen to the air as someone here remarked. But again, agribusiness doesn't really care because it all comes down to the economic equation of the price of ammonia and the price of corn. The economic payback from, for example, planting a winter rye cover crop may not be realized for several generations - therefore it is not done because agribusiness has no moral obligation to future generations only to living shareholders. 

.
 
Marco Banks
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Tom Turner wrote:
I do not understand why this is not the agricultural standard around the world.
.


Simply put, efficiency. 

My father grew up on a farm about an hour west of Sioux Falls SD.  In his day, they grew some hay, corn, oats and occasionally some barley.  They ran about 30 head of cattle on the pasture, along with hogs and chickens.  A small farm  -- 160 acres total.  One quarter.

From town out to the farm, there were 13 farmsteads.  Some of those guys were "big operators", farming a full section or 3/4ths of a section.  There were 2 people among those 11 who milked about 40 cows.  Grandpa sold them hay.  Shelter-belts cordoned off those farms --- long lines of trees every half-mile or so.

Today, if you drive that same road from town out to where the old farm was, there are now three farms that remain  You can't even tell where most of those old farmsteads were.  They torn down the barns, houses and outbuildings, cut down those shelter-belts, and removed almost all of the fences that subdivided those plots.

Not many oats and no barley grown today.  There still are a few hay fields, but corn is king and beans are second (soy beans).

The tractor my father used to use to cultivate corn had, perhaps, 20% of the power that today's machines have.  The ran a 4 bottom plow.  When grandpa got a big enough machine to pull a 6 bottom plow, they were beside themselves with joy.

Today, one farmer does what 8 farmers used to do.  All those tiny farms and tiny fields gave way to massive operations with massive machines.  Many of the fields are a mile square.  You don't have to turn your tractor around for a mile --- and at that point, a satellite tells the tractor when and where to do so. 

Efficiency.  Just that simple.
 
Tom Turner
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I still can't grasp the reasons why tilling should not be done. Personally I am weak on bio chemistry and this ignorance may prevent me from understanding. The reasoning seems to always distill down to the one, quite emotive, idea that tilling "destroys" the soil biome. That seems to me to demand some more information defining what "destroy" means because the bacterial and fungal communities continue on while individual organisms may die. The life cycle or turnover rate (like saeculum in human terms) seems critical here. Isn't bacterial life cycles just a matter of days. Fungus is slower growing, longer-lived, but what is it? After tilling is it merely 20-30 days before it has fully regenerated? - or even regenerated to a greater population because of the introduction of new organic material and fresh air into this fungal community. This calls for metrics not emotion. If, for example, I wished to grow as a product, that green mold which grows on bread I really do not think that ripping the the mold covered bread into little pieces would destroy my crop. The absolutely most important thing is to have bread to begin with. No bread, no mold. Lots of bread, lots of mold.

Now I'll give it my best shot at pro-Till:

The roots of plants grow in response to where the nutrients are. The individual root which finds nutrients hypertrophies. The individual root which finds nothing withers. Shallow nutrients, shallow roots. Deep nutrients, deep roots. (Is that true, or am I the victim of a popular myth?)

Another factor which no one has touched upon is the moisture holding property of soil. It's like thermal mass; highly absorbable organic material in soil can take in excess water during a rain event (minimizing leaching) and give it back during drought periods. It is the actual voluminous structure of organic material, like the wood fiber in a wood chip, which holds the moisture. When you top dress that voluminous fiber does not percolate down into the soil. The decomposition happens on the surface and the water soluble nutrients percolate down into the soil in the process of leaching. Or top-dressing could be thought of as a natural hydroponic system where all nutrients are water born and delivered to the roots by the movement of the water (like thermal convection vs thermal conduction). The problem is that water is hard to control without a system of containment like a sponge.

The best system is to have voluminous organic material (which holds fast to the nutrients inside it) down deep in the soil. And to allow the decomposition to happen down there while the living root takes up the nutrients as they are released in the decomposition, or disassembly, of that structured voluminous material. While this disassembly process is happening that structured voluminous organic material serendipitously acts as a sponge mitigating the damage of rain and drought cycles and ever ready to give a drink to the beloved minions of the biome and of course to the plant we intend to eat.

.

 
James Freyr
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There's a fantastic article in the April 2017 issue of Acres, USA magazine on page 76 titled Fringe Benefits: Embracing No-Till for Soil Health by Werner Wandersleben, Ph.D.. It provides reasons and helps explain why no one should be tilling.
 
Tom Turner
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There is a limit to the economic factor of the-economy-of-scale. The agribusiness large enough to buy two of the largest tractors available has no scale advantage over two businesses half the size with one super tractor each.

But there is no inherent limits to the geo-political-financial factor of the-power-of-big, the ability to control markets, set prices and force conglomeration. In 1880  JD Rockefeller Sr. said “The combination is here to stay. Individualism has gone, never to return.”  Even with it's warm-n-fuzzy Norman Rockwellian sacred image the individual family farm can not escape this ... unless we experience a radical social paradigm shift as we did in the industrial revolution of the nineteenth century.

That magazine Acres, USA says their philosophy is to always do what is best for the family farm. I have a different philosophy. Before the Civil War >90% of us worked full time in agriculture. Now <5% of us work in agriculture. I think it should be more like 75% of us should spend 10% of our time in feeding ourselves. That would still allow a generous deficiency due to a loss of economy-of-scale. You once said that less physical work is an advantage of No-Till, but I think increased physical work is a solution to our social pathos' of obesity and the stress of the frenetic pace of consumer society. I'm a distributist and feel we should work towards GK Chesterton's ideal of two acres and a cow, not because of any economic efficiency or even sustainability, but because it is a happier and healthier lifestyle.   

.
 
Marco Banks
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Tom Turner wrote:There is a limit to the economic factor of the-economy-of-scale. The agribusiness large enough to buy two of the largest tractors available has no scale advantage over two businesses half the size with one super tractor each.
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Like any other business (and perhaps, even more so on a farm) it's all about management.  A good manager makes money, while a poor one doesn't. 

If a good manager can get a reliable employee to run one of those two large tractors for a reasonable wage -- (for example, lets say $10 an hour, about $100 a day, as nobody works an 8 hour day on the farm), while he runs the second tractor, he farms twice the ground but splits the profits of his enterprise with no one.  That's good management.  If he has three employees, he can farm 3 times the ground he could do himself, and after he's paid those two guys, he keeps 3 times the profit.

Further, its usually far more efficient to have more than one person working.  You keep the combine running while I truck the grain to the elevator and bring back the fuel truck to top-off the tank so you can keep combining.  You run into town and take care of these errands --- I'll keep seeding (or whatever the task).  One of the biggest variables on a farm is the weather.  Farmers have a limited window to get their crop in and to take it off.  Being able to hire someone part time for these short windows to time allow them to farm significantly more.  One man could milk 30 to 40 head of cattle while keeping everything else running.  Two are be able to milk 100.  Maybe more.  Three are able to milk 300 or more.  Again, if I'm only paying you wages but keeping the profits on the milk from such a large herd, that's significant.

Most of the farmers I've ever known do not pay themselves a salary.  They pay for their expenses and splurge on a new car or vacation from time to time, but the majority of any profit they make is plowed (pardon the pun) right back into their operation.  Again, the best managers make money, and leave to their children a profitable farm with no debt.  So taking on extra employees to farm more land, without sharing those profits beyond just paying their wages, allows that farmer to invest more money back into his operation.

Thus, the economy of scale is that if I'm able double my land under cultivation, the expense of paying an employee if far less than the money I make by doubling production.
 
Ben Zumeta
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Tom - "I still can't grasp the reasons why tilling should not be done."

It helps to start with asking, "why are you tilling?" It seems largely to increase the immediate availability of nutrients and air by reducing particle size and increasing surface area.  This works in the short term to increase the mass of bacterial life if organic matter is continuously added. But in both respects the benefits are short lived and require continuous maintenance. The reason you are taught this is the best you can do as a farmer is because this makes the equipment producers money and so they pay your state agriculture school to say so. 

Do an experiment yourself or observe in nature how, in the long run, a mulch of woody debris and leaves of all shapes and sizes creates the most stable structure for air and water to penetrate and balance each other, facilitating continuous availability of nutrients at the plants demand through fungal networks. In old-growth forests these fungal networks can extend up to two miles though the roots of the largest redwood trees go out "only" 80-200ft at most. This allows them to literally trade nutrients, water, sugars, carbon in order to maximize the productivity of the entire system. Try as you might, and I am sure you have done so valiantly, but it is impossible for a single farmer or hundreds of hands to replicate the alchemy that thousands of species of fungus can summon in order to propagate the plants they need to survive. And ultimately, the bottom layer of a healthy forest is a healthy fish stream, which is another 20x as productive of protein as any land environment.
 
Gilbert Fritz
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I think the main goal of soil disturbance is to prevent succession. Disturbance changes soil structure, biological processes, temperature, and water movement in the soil; this favors annual plants. Of course, there are other ways to prevent succession, such as the crimper roller used on organic no-till, or herbicides. But on a small scale for organic farming tilling seems to work well.

Of course, if one is growing perennial tillage will be minimized or eliminated.

But scrapping all the work humans have put into developing annual crops seems unwise. Besides, have you ever wondered why humans put so much work into annuals compared to perennials? This is particularly so in temperate climates.
 
Todd Parr
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Gilbert Fritz wrote:I think the main goal of soil disturbance is to prevent succession. 


I think you are exactly right that that is a major goal of tilling, but would argue you can do the same thing by piling on mulch or planting cover crops continually.  "Scrapping" tilling does not mean "scrapping" annual crops in my mind.
 
Gilbert Fritz
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Todd,

I agree that there are many ways to keep succession from proceeding. But on a large scale ( over a quarter acre or so) mulch becomes less useful for growing annuals. It greatly impedes the efficiency of a system. Also, hauling in that much mulch does not seem sustainable. It can cool the soil, and can over time, if imported, imbalance the soil minerals. Particularly for grain crops mulch is not a viable strategy.

Cover crops are useful, though they often need some sort of soil disturbance to terminate them.

In any case, killing cover crops with a crimper, spreading mulch, or using tarp to kill weeds all disturb the pre-exisitng ecosystem to some degree. Our goal is not necessarily to minimize disturbance, but to maximize ecosystem health while at the same time feeding ourselves.

On my quarter acre plot garden plot, we plowed to break the heavy sod the first year. This year, we are using a broadfork to loosen the soil and using hand tools to cultivate the surface. We may use a tiller to cultivate the top half inch of soil if the weeds start to get ahead of us. Once the weather warms up, we will use a bagging mower to collect grass clippings and spread them around some crops. Over time, we plan to use lots of cover crops and continue our minimal tillage, leaving most of the crop debris on the surface as a light mulch. We will also use tarps to kill off cover crops.

The only drawback to this minimal tillage seems to be that it is harder to get a fine seedbed for small seeds such as lettuce.

Now, does this minimal tillage damage the soil? That is a difficult question. In between each 200 square foot bed we have a wood chip mulched path that is never tilled; so I imagine that fungi will develop well in the paths and rapidly spread out into the beds to capitalize on the extra nutrients there. Worms have increased rapidly from almost zero since we started working the area. But determining ecosystem health is difficult. Everyone seems to have different metrics.

On a previous plot I used a foot of wood chip mulch over cardboard, and found it to be too much work. I was also less then impressed by the results. Weeds rapidly reestablished, and were impossible to hoe down in the mulch.

Even the co-founder of permaculture, David Holmgren, has criticized the way that deep mulching has come to be seen as "the" permaculture way. He says that deep mulch should be seen as a one time soil preparation step. After that, three things can happen to a mulched bed; succession can be encouraged to turn it into a food forest; more intensive cultivation can keep it growing annuals; or it will be reclaimed by grass and weeds, eventually to succeed to whatever climate vegetation is in the area.  Heavily mulching an area every year, or even every few years, while continuing to grow annuals is not a viable or desirable strategy in his mind. This discussion is in his book Permaculture: Principles and Pathways Beyond Sustainability.
 
Tyler Ludens
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Gilbert Fritz wrote: Besides, have you ever wondered why humans put so much work into annuals compared to perennials? 


http://discovermagazine.com/1987/may/02-the-worst-mistake-in-the-history-of-the-human-race

http://kennysideshow.blogspot.com/2008/05/agriculture-or-permaculture-why-words.html
 
Gilbert Fritz
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Post Today 8:37:47 AM MDT     Subject: To Till, or Not to Till, and WHY
Gilbert Fritz wrote:
Besides, have you ever wondered why humans put so much work into annuals compared to perennials?


http://discovermagazine.com/1987/may/02-the-worst-mistake-in-the-history-of-the-human-race

http://kennysideshow.blogspot.com/2008/05/agriculture-or-permaculture-why-words.html


I found this discussion on Small Farm Future useful. http://smallfarmfuture.org.uk/?page_id=714

 
Tom Turner
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Ben Zumeta wrote: It helps to start with asking, "why are you tilling?" It seems largely to increase the immediate availability of nutrients and air by reducing particle size and increasing surface area.  This works in the short term to increase the mass of bacterial life if organic matter is continuously added. But in both respects the benefits are short lived and require continuous maintenance.


Ah, another "Why" question. Like a 4 year old I like "Why" questions. For me it is always and only to add soil amendment. If one year I had nothing to add I wouldn't till.

I'm beginning to see this debate as a value judgement. Does the Virtue of soil amendment overpower the Vice of tilling? Or is there nothing that can justify the Vice of tilling? And as I mentioned before I think emotion plays the biggest role here. And that includes me because I adore the feel and smell and sight of rich dark organic material, it makes me emote positively about the Virtue of soil amendment.

I've heard the argument many times now that soil amendment is "short lived,"  like an algae bloom that explodes and then disappears without a trace. Empirically I can say that's wrong. I moved into a house that had a existing garden plot. It had about 5-6 inches of good top soil, which my neighbor told me came from his cow's backsides (he wanted to continue selling his manure). I began a system of amendment tilling spring and fall and adding much organics both times. The soil was always covered, by hay mulch after the spring till, and by winter rye cover crop after the fall till. In just a few years I had 12 inches plus of really rich dark soil that made me emote a happy dance. It grew champion tomatoes and peppers. But I can't vouch for it's nutrient balance or suitability to grow different things or any number of things that the knowledgeable people here could observe.

Then due to too many pans in the fire I abandoned gardening altogether (gasp) and  turned it over to lawn. For the next 5 years, until I moved out, I observed people's lawns. lawn care becomes a sort of competition among people with jobs. The approved way of lawn care is with lots of chemical fertilizers; poisons; irrigation; removing clippings and an occasional aeration or de-thatching (which is the removal of even more organics). When the mid summer heat hit everybody's lawn turned brown despite all the above high tech efforts - everybody's except my section of lawn over that 12 inches of rich top soil. It was perfect through every drought period. In the 5 years I watched this there was no signs of the lawn quality deteriorating at all. It was not short-lived. It seemed pretty permi-nent. Now maybe you guys are explaining to me why. Perhaps that section of lawn which didn't get tilled any more had an extensive network of long thread fungi living large on all that organic material I put there. Was it the result of me and the fungi working as a team?

For whatever the reason I'm quite sure of the empirical fact that the best way to have a perfect lawn is to have 12 inches of rich topsoil under it. So over the years I wondered how to get 12 inches without starting from scratch. This is basically how you do it:

Of course this is a woefully inadequate 2-3 inches, but it is the right idea. And incidentally, it is the same idea the wonderfully diligent and heroic Ants use to produce that 36 inches in the Prairie Paradise -  Paradise now lost.

Imagine a machine which looks like a combine. In place of the leading edge sickle bar would be a long arm of rotary core drills about 2 inches in diameter and capable of drilling 24 inches deep, spaced every 2 ft down the arm. Instead of the grain container in the back of the combine, there would be a tank of organic slurry and a pumping system. The machine, would drill a line of about 20 holes, a swath 40 ft wide, withdraw the drills and inject the slurry. It would advance 2 feet and repeat the process (which I imagine could be done in a cycle time of about 5 seconds or less). It would require tender trucks bringing in more slurry. The whole process would proceed much slower than any current plowing or harvesting operation, but there is a factor here: A unique aspect about agricultural equipment is that there a very small window in time which the equipment must do it's job. It then sits idle for the vast majority of time. In all other industries the very expensive equipment they invest in runs long hours to yield the economic payback. Plastic injection molding might be the opposite of agriculture. Once they get a molding machine in cycle (thermal equilibrium) they never turn it off. It runs 24/7, the psychological stress it causes third-shift workers notwithstanding.  But this Core-Drill-Organifyer, lol, could operate at any time, even with crops in the field or in frozen ground in the dead of winter. It could operate around the clock providing a much better return on investment, more like manufacturing equipment. The basic system could also operate in any agricultural environment including grapes and orchards (with some configuration adaptations).

Would this not give us the Virtue of organic soil amendment -and- the Virtue of happy and well-fed long thread fungi?

.
 
Gilbert Fritz
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A less mechanically oriented mechanism is as follows; a chisel plow is pulled through the landscape on contour 1 foot deep, creating optimum mechanical conditions for growth. A crop of rye, Sudan grass, or other deep rooted cover crop is immediately planted, and every time it gets a foot tall is mowed down. The grass quickly fills the top foot with roots; a single rye plant can grow several MILES of root in a season.

The next year, the chisel plow is pulled through at a deeper level, say a foot and a half, and the process repeats. Within a few years, tons of organic matter has been added. The machinery, chisel plow and rotary mower, are being used to "pulse" the system, greatly increasing the amount of organic matter added.

I'm not sure that any system of bringing in outside organic matter can be sustainable over the long run and with a large area. In the short term and with a small area it is a useful technique.

Another reason to till is that planting some crops, such as grains, requires a fairly fine seedbed. Of course, grains can be drilled into the ground in no-till, but this means the use of a specialize piece of equipment; "tilling" the ground can be done with much cheaper equipment, or even by hand.

The Biointensive method can researched in this connection. They double dig the soil every year, and under their method organic matter quickly builds up in the soil. (They don't import organic matter except at the start of the project.)

Finally, on a large scale, tilling can be a useful method of suppressing some weeds. On a small scale a foot of much does an excellent job. But covering even an acre with mulch is difficult, to say the least.
 
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