Building soil and "building soil"

I don't know if anyone has pointed this out yet, but a lot of the time when we talk about "building" soil on here we are actually talking about IMPROVING soil, more specifically the subsoil. Most places where we are gardening/small farming there are at least a couple feet of subsoil to be worked with and this leads to some overconfidence perhaps on what could be done under less ideal circumstances. Things like sequestering carbon, increasing organic matter, and developing the soil microbiology all have to do with feeding the subsoil and turning it into more topsoil.

I think if you were trying to literally build soil, as in somewhere with an inch of soil and then bedrock, things would be a lot harder and slower and closer to the "inch per five hundred years" we're told is science. Of course, that is nature and 500 years is pretty quick on a geological time scale and I'm sure the processes could be sped up a lot. But I also don't think anyone would be building a foot of soil in five years or whatever like you see on the internet from people with plenty of subsoil. Maybe 2 or 3 inches per generation or 5 or 6 inches per lifetime would be my guess.

I have no experience with this though. Anyone on here live on bare rock with an inch of scraggy topsoil or something like that?  Or otherwise have experience building soil where there's no subsoil to be improved?  I'm curious as to what your results have been.

I have areas like you are talking about.  I haven't done it on actual rock, but I don't have any doubt at all that I could build a foot of soil in 5 years.  If you are talking about a small area, I could build much more than a foot in that time, it just takes lots of inputs.  You can build a foot of soil in 5 years just by making a pile of wood chips 5 feet deep and dumping compost and minerals on it over that amount of time.  Not on bare rock though.  

I guess we would really have to agree on the definition of "Soil".  My understanding is that soil is particles of rock of whatever size, minerals, organic material.  I can't make the minerals, so if you mean that, I guess we agree, you can't make soil in any length of time without machinery.  But my idea of making "soil" is starting with dirt.

I kind of had low input natural farming in mind, over acres not just a spot.  

L. Tims wrote:I kind of had low input natural farming in mind, over acres not just a spot.  

Without inputs, I agree with you.  I don't know how you would ever build soil faster than nature is going to.

Trace Oswald wrote:You can build a foot of soil in 5 years just by making a pile of wood chips 5 feet deep and dumping compost and minerals on it over that amount of time

I would call that moving soil although it's debatable as you are starting with soil ingredients rather than actual soil.


I plant trees in solid rock by smashing a crater and filling in with the rock bits that I smashed out. The area further out than the crater starts to be populated with "weeds" if I water my crater, and thus soil is built. Easily at the rate of an inch per year.

Here's a thread describing an experiment in making soil from rock by our Soils Science Expert(like, as in, and actual scientist) Dr. Bryant Redhawk (all his threads about soil are amazing and helpful, by the way) -

https://permies.com/t/93911/soil-mother-nature

Chop and drop, cover crops, fermented compost tea to make better use of what manure is available, stuff like that.

I've seen his threads Dustin I just haven't seen this sort of thing addressed. It is very helpful information though.

I have read Redhawk's excellent information, and learned much from it.  As far as this thread, it seems we are just discussing the semantics of it.  If I have dirt and I add compost, which brings with it soil life, in my mind I have just built soil.  Improving soil seems to mean I already had soil, I just made it better.  I don't know how that is possible without inputs.  

I think we're on different wavelengths here Trace. You can't imagine a scenario where you have, say, five acres of land with no subsoil to work with and you have to find a realistic medium between waiting thousands of years for it to build itself and paying a million dollars to have five acres worth of topsoil and compost trucked in?

You aren't gonna get enough woodchips to cover five acres to a depth of one foot, and even if you did there are all sorts of complications that come with that like how well they break down in your climate, erosion and how much soil they actually break down to (not a foot).

As for the minerals, they are there already they just have to be accessed. Decay creates acids which are just as  capable of breaking down rock as machinery.

L. Tims wrote:I think we're on different wavelengths here Trace. You can't imagine a scenario where you have, say, five acres of land with no subsoil to work with and you have to find a realistic medium between waiting thousands of years for it to build itself and paying a million dollars to have five acres worth of topsoil and compost trucked in?

You aren't gonna get enough woodchips to cover five acres to a depth of one foot, and even if you did there are all sorts of complications that come with that like how well they break down in your climate, erosion and how much soil they actually break down to (not a foot).

As for the minerals, they are there already they just have to be accessed. Decay creates acids which are just as  capable of breaking down rock as machinery.

Yes, I can imagine a scenario like that.  I think you mentioned the two extremes.  I can imagine a scenario anywhere in between.  You could bring in truly massive amounts of inputs and build soil really fast, or you can bring in smaller amounts of inputs and build soil at a slower rate, or you can bring in very small amounts of inputs and build soil at a really slow rate.  I can't really think of a scenario that is outside of that sliding scale anywhere, but that could very well be my own shortsightedness.

I watched a youtube video about a couple that had just over 500 dump truck loads of wood chips delivered to their two acre property.  They got them for free.  Their land had a slope that they wanted to level out, so they put wood chips anywhere from two feet to five feet deep over the entire two acres.  They moved every wood chip with a wheel barrow.  They created soil more than two feet deep in some areas I think.  I don't remember for certain, but I believe they said it took about three years to create really great, deep soil, and was building more all the time.  Granted, this isn't practical for most people, but they showed it can be done.  The results in the plants they grew were amazing.

As far as decay creating acids that break down the rock, it is my limited understanding that that is the way, or one of the ways, nature does it, and that is why it takes hundreds of years.

It seems that something I posted in this thread bothered you in some way, so let me apologize for it.  I was simply trying to add to the discussion, but I'm happy to remove myself from this one.  Best of luck to you.

I have not read all the posts here in this thread yet, but I can that this right up my alley!!! I'll read everything, then make some intelligent comments. But for now I can say that building soil can be done, not just improving soil, but actually creating it. I've done it and doing it on a moderate scale. In the matter of 4-5 years I've created a 700 square foot garden area atop a concrete slab where the garden soil is now 6"-8" deep. I'm just now harvesting my crop of turmeric from this spot, having sold two 5 gallon buckets of it just this very morning. That's just a tiny fraction of the anticipated harvest. Last year's crop was taro.

I also have 6 large hugelpits that are entirely created soil. Two of those pits were large enough to completely swallow my F-150 pick up truck if I have been stupid enough to drive it into them. The other 4 pits are smaller, but not small by end means. It took 10 years to create those pits full of garden soil (about 4 to 5 years per pit) and they now support healthy crops of bananas, taro, and sweet potatoes. Because the soil is still extremely young and decomposing, I need to repeatedly add more material to each pit.

Yes, I used a lot, lot, lot of input materials : organic waste material of all sorts (garbage, weeds, grasses, ground up brush, wood, cardboard, waste paper, manures, coral sand, lava sand, volcanic cinder, dead animals & slaughter waste, wood ash and char, bones, compost, mulch materials, rocks (yes, rocks). Plus healthy garden soil used as an inoculant.

I wanted to relate what a fellow named John accomplished on his property in Oceanview, Hawaii. In the matter of a couple years (maybe 4 or 5 though I never kept track) he transformed his 100% lava 1/2 acre into a garden capable of supporting annuals, perennials, and orchard trees. His soil is now 12"-15" deep. Atop his fractured lava he repeatedly dumped pickup truckloads of what we call "county mulch". Our county diverts green waste from the dump and grinds it up. The material is mostly coconut tree trimmings mixed with any other sort of green waste, including some dirt attached to the roots. This county mulch can be hauled away free by the island's residents. John made a point of bringing a truckload back from every trip to Kona, sometimes one every week. As far as I know, he's still at it, expanding his garden areas. Before long he will have an acre of deep soil. He owns other land adjacent to his home, and I assume he will next focus on those acres as well. So he's an example of creating soil over a larger area, in his case it will be a few acres. It just takes lots of material, time if you're hauling it in small quantities, and perseverance.....and of course, a good source of materials.

One feature of my gardening style is the use of what I call grow boxes. They are four wood pallets nailed together to make a box, lined with a moisture deterring material (sheet plastic. Sorry Paul, but I haven't come up with a permaculture alternative yet) so that the compost/soil inside them doesn't dry out, I get a lot of wind where I am, so unprotected compost bins and container gardens dry out quickly.  Some of these boxes are used to create composts of various types. Some are used for growing crops.

Some grow boxes are filled with a compost-soil mix that is used to grow a crop. Actually, my goal is to create garden soil, but I take advantage of the method to also grow a crop of food at the same time. Ah-ha, I'm stacking functions.

To fill a grow box I alternate layers of fresh compostable materials with a thinner layer of compost-soil mix taken from a previous grow-box from which I've harvested a crop. Thus I'm always reusing/recycling created garden soil. Mixed in with these layers are smaller additions of what I call soil amendments -- coral sand, lava sand, volcanic cinder, processed bone, wood ash and char, ocean water. I used to add garden soil, but since I'm recycling material from a previous grow box, I'm no longer separately adding garden soil.

To fill one grow box takes a lot of material. Once filled it is one cubic yard of material. Over to course of one crop season, the material decomposes down to 50% of its original volume. So this process gives me, on average, 1/2 cubic yard of very young garden soil. This material continues to decompose, so if I were to leave it in a grow box, it would become less and less volume over the years. This doesn't surprise me at all, though I've had many a new gardener become baffled about their garden soil "disappearing". Some of this new garden soil is recycled into the next grow box, but most either goes into my main garden areas or for creating new garden spots.

I currently am running 39 grow boxes, thus I'm creating close to 30 cubic yards of new garden soil a year.....some of those grow box crops are on a 9 month growing cycle, while others mature out at 5 months. By the way, that represents truckloads of input materials.

Hey Steve Farmer, just noticed your awesome comment. I like the sound of your method of breaking up a "crater" in the rock and planting a tree in it. What kind of trees work best for this?

Su- lava rock actually seems seems like it'd make a good base material for soil, rather than just something to be built on top of. The soft airy crumbly kind I mean, I think that's what you're talking about, not obsidian or something, haha. If that's what I were working with I'd probably try taking a pick and a mallet to it and seeing if I could get it broken down to something I could add a bit of organic matter to and then grow in.

Also, you've got an awesome potential cash crop, pure unblended Kona coffee costs a fortune! Maybe you're sick of looking at it though lol.

L. Tims, a small part of my farm sits upon pahoehoe lava, which can be hydraulically hammered but difficult to impossible to break up by hand. It takes tens of thousands of years for plant roots to break it down into crumbles of any sort. My main garden area is atop pahoehoe (2+ acres). In the past, this area was flooded at least once with severe runoff from heavy flood rains coming down the mountain....as evidenced by the smooth pahoehoe being covered in a layer of rocks generally between soccer and basketball size , and mineral debris found between the rocks (cinder, sandlike material, and some soil). Upon removing the largest rocks. I was left with 1"-2" inches of "soil" over the pahoehoe. In most places the pahoehoe is fractured, thus rain will drain through it with no standing water left behind. So I can grow on it.

The rest of the farm is a'a lava, which is jumbled lava that has a solid core beneath the jumble. I can actually dig a hole to plant trees as long as I am using an o'o bar (a heavy solid metal bar about 5' long) to pry the lava chunks up. The lava chunks range from baseball size to bigger than a car. Thus I have to be flexible about choosing a spot to plant something, for I'm surely not going to break through the big boulders using hand tools. The a'a area is geologically older than the pahoehoe area, thus it has a decent layer of decomposed material mixed among the rock. It's a type of soil, though it's not very fertile and it tends to be hydrophobic. This soil grows native trees adapted to this base, plus ferns and pasture type grasses. Not much else grows without help.

I agree that the lava gives a nice mineral base to work with. But I'm not fortunate enough to have a volcanic cinder base to make my life easier.

Per Kona coffee......I currently have about 200 coffee trees on the farm, enough for our own use, plus gifting. I live in the district of Ka'u, which means that I can't sell Kona coffee (to be Kona coffee, it must grow in either South Kona or North Kona districts). But actually, Ka'u coffee sells for more than the Kona does. But it's a difficult business to earn a living with. It's a lot of work and costly to do. I did it for 2 years and learned the hard way that it's not something I want to be a slave to. The market is too fickle. The competition is fierce. And although I made a profit, by the time you figured your expenses and costs of doing business, I was working for about $2 an hour with no guarantee that there wouldn't be a crop disaster of some sort. So I ripped out most of the trees and planted veggies. One thing about coffee though, it will grow in pure lava. Veggies won't.

I plant trees in solid rock by smashing a crater and filling in with the rock bits that I smashed out. The area further out than the crater starts to be populated with "weeds" if I water my crater, and thus soil is built. Easily at the rate of an inch per year.

I remember that thread Steve, what an awesome experiment - can you link that thread here, and maybe post a few update pictures to it so we can see the soil you've built?  

Another option for "mass amending" the soil would be:

Sign up for Chipdrop
https://getchipdrop.com/aboutus/

and find posts on Craigslist about free fill dirt, or post your own requesting free dirt/free trimmings dumping.

Then spread dirt, plant "weedy, thrive-in-any-soil" types of crops, mulch, and wait; this would get you crops in one year, and better soil in three years, instead of five with waiting for green manure to grow to chop-and-drop. Daikon radish and alfalfa(and many other potential species) for quick, deep roots to start to bust open cracks in the bedrock.

i know my previous post isn't exactly what you're looking for, but if you want to turn rock into soil with no inputs(soil, compost, chemicals or fertilizer,) and no mechanical intervention(skiploaders, mining equipment, etc.), all that is left is human/animal power - or buying new land.  

I'll take soils amendments and plant power over moving or breaking out the pickaxe any day.

When we lived in Central Texas some years ago, we had limestone/bedrock for soil ;). To top it all off, whatever grew there was grazed down by the previous owners' 7 horses (which they kept on 5 acres). The only things living were sneezeweeds which nobody wants ;). Soil (whatever there was) was compacted as well and hard. The thing I did for years was pile own own horses' manure on whatever was below. I planted in the manure, things like everyday veggies - tomatoes, broccoli, peppers, eggplants, even things like corn. There were areas with better/deeper subsoil and in those I planted potatoes and sweet potatoes. I knew I would throw away a lot of the unsuccessful plants but their roots did penetrate and break up soil for the next year. After a few years of doing so (and getting some low but acceptable harvests), the soil became deep enough to actually grow something in. Without manual, outside supplementation of organic matter, one is pretty limited in what they can do... One other thing we did was plant annual ryegrass and try working that back into the horse manure it was planted in...

I found Steven's Crater Thread!

https://permies.com/t/48718/plant-tree-solid-rock

It would be interesting to see how much biomass/soil has accumulated in the crater since the initial planting, whether from passive dropping from the tree, animal activity, or degradation of the bedrock...

Steve, hammering holes into rock to create a crater is how farmers go about planting new orchards in my area too. 1/4 mile up the road from my place is a 200 acre macadamia nut orchard. The ground was initially bulldozed to remove native growth (trees and brush), then ripped & bulldozed to smooth it out into plantable sections. The ripping broke up the lava surface down to about 6"-10". Every tree was planted into a hammered crater, one by one. Each tree sapling was planted along with a backhoe sized scoop of macadamia nut processing debris (hulls & shells from the previous year's harvest). Most of the debris acted as a mulching ground cover. Once a section of saplings were planted, the rest of the available macnut processing debris was applied as a thin top mulch between the trees. Grass was seeded into this. As the grass grew, it was mowed to provide clippings to help cover the lava. Commercial fertilizers kept the grass growing aggressively, thus lots of clippings became available to be blown into the tree rows. After a few years the newly planted sections looked beautiful. After 15 years of work, all 200 acres is developed and producing. The orchard is now at maintenance level.

I just walked up to the orchard last night to take a closer look. It's the prettiest macnut orchard I've ever seen, but I'm aware that a considerable amount of commercial chemicals and fertilizers contributes to that. But I was curious about the soil. Under the trees is what appears to be fine grained, 2 inch deep soil. This is because of the mechanical nut harvesting which churns the top inch or two and removes any rocks nut sized and larger. So after a few harvests, only fine particles remain. Scratching below 2 inches I came upon chunky lava mixed with fine dirt. Checking the ground out from the trees into the alleyway, the lava chunks were at the surface, mixed with dirt. I could not easily check down deeper than 3 to 4 inches because of compaction due to farm machinery. I had no handpick with me. But what I saw indicated that dirt was being created by the constant application of grass clippings, fallen tree leaves, annual applications of harvesting debris, and the action of soil life and turkeys. The farm hosts at least a hundred feral turkeys who roam under the trees.

It was interesting to see 200 acres that I knew started out as raw chunked lava rock turn into dirt and rock in such a short period of time. Outside of the initial macadamia nut harvest debris that was used to plant the saplings, all additions came right from the farm. Wow, 200 acres turned into dirt & rock in 15 years. There's enough dirt to grow just about anything, although the ground is indeed rocky. One could not use plows or tillers without doing some serious derocking first. But I could readily garden there using hand tools. Daikon, carrots, parsnips, sweet potatoes would be funky looking, but non root crops would be growable.

15 years ..... 200 acres ..... minimal outside additions. Amazing. Don't get me wrong though. It's not deep garden soil. But it's ag soil suited to orchards, pastures, and grain production. In only 15 years.

Su Ba wrote: The ground was initially bulldozed to remove native growth (trees and brush), then ripped & bulldozed to smooth it out into plantable sections.

Nothing like working in tandem with Mother Nature, eh? ;)

Oddo, I'm relating information about a progressive commercial farm. But surprisingly to some people, here's an example of a modern commercial farm that is using several permaculture methods.
...natural windbreaks created using the original forest
...wildlife set aside areas
...honeybee colonies
...ground cover crop
.,.mulching
...on-farm inputs
...soil creation/improvement
...natural irrigation (rain + mulching)
...centipede and slug control via feral turkeys

This farm surely isn't an example of permaculture. There is aggressive use of chemicals. And as you noted, the natural forest was completely bulldozed....an essentially monoculture ohia forest with a small percentage of other plants. It was replaced with a 90% monoculture food oriented forest. But then I think.... permaculture isn't about leaving Mother Nature au natural. It's about agriculture done in a sustainable fashion for the foreseeable future.