Fertilizing rocky soil where it's half soil half stones (and no dirt)

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This is my *best* soil:
http://i.cubeupload.com/ixJt7h.jpg
It's half stones:
http://i.cubeupload.com/czWmKi.jpg
Hence two questions ... Q1: Is your soil rocky like this?
http://i.cubeupload.com/lEPHQG.jpg
Q2: If so, how would you fertilize it?
The wife wanted planters for the grandchildren to put their food in so that the kids could revel in the wonders of tomatoes and melons and peppers grown from their own leftovers.
So she asked me to get her a couple of 5-gallon buckets of "soil" (she called it "dirt" but dirt and soil, I was told by my college professors, are two different things - but no matter how many times I tell her the difference - she still calls it "dirt").
I went to the lowest area of my property to find the most non-rocky soil I could find (yes, "rock" is different than "stone", as outlined by the same college professor); but even then, thousands of feet away from the bulldozed areas, I still ended up with 100% Franciscan sediments currently weathered to 50% stone and 50% smaller particles.
I sifted out with a quarter-inch grid the smaller particles, but the result is still a coffee-colored mix of what seems to be relatively infertile soil.
How would you fertilize this stuff sufficient for kids to grow plants?
http://i.cubeupload.com/KlXcvs.jpg
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Add water.
Alternately, go get a bag or two of potting soil.
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On Tuesday, September 6, 2016 at 6:27:12 AM UTC-4, dadiOH wrote:

+1
Or if there is use for enough, for a couple hundred bucks he can probably get a load of topsoil delivered. If he has a large lot, it can be left in a spot for use over time. For that or his existing soil, a general purposed 10-10-10 type fertilizer should be fine. I'd test the soil PH though, who knows what it is, and adjust if needed.
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On Tue, 6 Sep 2016 05:20:33 -0700 (PDT), trader_4 wrote:

I know that I can get potting soil but this is a "nature" experiment, so, the natural soil is the goal, so that the kids use their own soil and their own waste food to grow their own food plants.
It's really an experiment and not a commercial venture. :)
I'm more curious if your soil is as stony as mine. Is yours half stones?
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On Tue, 6 Sep 2016 06:27:01 -0400, dadiOH wrote:

Funny you mention the water, as I looked up how roots uptake nutrients.
I was debating whether removing the stone chips helped or not. On the one point, the stones may create cavities for the water. But on the other hand, the roots would be forced to go around the stones. Besides, the water remains, I thing, by capillary action, around the soil nodules.
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On Tue, 06 Sep 2016 12:39:27 -0700, Oren wrote:

Do you think it's a good idea to "loam" the soil by mixing in some uniformly sized sand grains?
I was wondering if I could grow a horse radish for myself from the condiments I have in my refrigerator! :)
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On Tue, 06 Sep 2016 15:12:53 -0700, Oren wrote:

Hmmm... I guess "cemented" soil is bad, I guess. So, from that 'sandpoint', the sandy soil may be better for drainage.
But, um, what is the problem with water. Plants need water to live.
And, they don't "drown" since they don't have lungs so they don't "breathe" either.
I guess if the roots are very wet for a long time, they may get diluted of their ATP and other chemicals necessary for life, by osmosis into the water.
Is that what the danger is of too-wet soil? And how do you know it's too wet?
So many questions, so much I don't know.
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On 9/6/16 6:09 PM, Danny D. wrote:

Look up compacted soil or soil compaction.

More reading: http://scienceline.ucsb.edu/getkey.php?keys0

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On Tue, 6 Sep 2016 19:49:57 -0500, Dean Hoffman wrote:

I guess I need to look it up because the plants I know can drill through solid rock it seems. SO the roots find a way.

I never understood when people say plants need to "breathe" as if they had lungs, or that they can "drown". I understand the use of flowery words but they really don't tell me anything since plants don't have lungs.
Looking at the URL ... http://scienceline.ucsb.edu/getkey.php?keys0
I had not realized that plants use oxygen to burn sugar to make energy; I had always thought oxygen was a waste product for plants (which it is). I didn't realize it's *both* a waste product by day and a necessary product by night. Apparently it simply excretes more oxygen from the green parts than it consumes from all the parts of the plant.
The roots aren't green. So the roots need oxygen. They get that oxygen from the air spaces in the soil. *that* is why they can *drown*. They actually need air at the roots. Who knew that roots needed air? (I always thought putting roots in air was a bad thing.)
So much I don't know...
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Danny D. wrote: ...

if you are planning on growing root crops (like carrots) you don't want large stones in the soil.
besides, it's tough on the hands to work in a garden bed if the soil is full of stones (and tough on garden tools too).
smalls stones can provide some basic nutrients via fungi and other processes which break things down (plant roots/exhudates, bacterial stuffs, freeze/thaw cycle, water leaching, wind and rain motion, worms grinding...), but you don't usually need a lot of those in comparison to the more common nutrients known to be useful for plants (N, P, K plus many others too).
there's entire books written on this topic, but what you can do for most soils to help without having to do any testing at all is to add organic matter which will also help adjust pH and improve water and nutrient holding capabilities.
i've never tested the soil here at all. when i first started growing veggies they didn't do as well as they could. now things go much better.
songbird
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On Tue, 6 Sep 2016 23:25:45 -0400, songbird wrote:

Why not? I guess if there were a huge boulder, the carrot root couldn't get past it; ub what if there were just the small stones that are in my soil pictures. Can't a carrot root just push them aside or wend their way around it?

True. I tried to dig out a baby oak tree, five inches tall, for the grandchild's biome and the first sound of the shovel hitting the soil was that rocky gravely sound of scraping against pavement.

Hmmm.... small stones harbor fungi. I guess that makes sense since the stones probably create little caves and niches like where Neanderthal man lived in a larger set of caves.

I'm agreeing with you that there's probably no organic matter in this soil so if plants need organic matter, then I have to add it.
Interestingly, when I think of "fertilizer" I think only of NPK and not of Carbon-based life - so I'll look up exactly *why* plants seem to want to eat other plants and animals.
What Does Organic Matter Do In Soil? http://www.noble.org/ag/soils/organicmatter/
Hmmmm... that says the plants don't *eat* the organic matter; it says that the organic matter acts like the *sand* that someone else suggested, which prevents compaction but it also cryptically says the organic matter is a "reservoir" of fertilizer (which is slowly released into the soil).
They make a distinction between organic material (e.g., a dead leaf) and organic matter (i.e., the humus left after most of the leaf has decomposed).
Only 5% is decomposed yearly after the initial decomposition, and, get this... It is the stable organic matter that is analyzed in the soil test!
Who knew? Not me.
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Danny D. wrote:

you don't want crooked or reasons for the root to split.
...

no, the fungi will extract nutrients from rocks stones if needed. they also can act as transport agents to get nutrients to plants in exchange for sugars and other goodies. soil and the soil community can be complex. there's millions of bacterial species (many which haven't even been classified or studied yet) and fungi, virii, etc.
the more diverse you can make a garden soil the more resilience you have for handling different conditions and a balance between the good kinds and the kinds which can cause diseases.

humus and various compounds of late decomposition are weak acids and large molecules that can hold up well for years if not abused (excess N increases the rate of decomposition).
some types of soil carbon are even more stable and will be around for hundreds or thousands of years. best thought of as a very large surface area for bacteria and fungi. bacteria and fungi are your basic support system for long- term fertility (in combination with your mineral elements). you'll see terms like biochar used too. very useful stuff for poor soil, but it needs to be mixed in compost and aged for a while to give it some nutrients/bacteria/fungi/ etc.
songbird
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On Wed, 7 Sep 2016 11:23:29 -0400, songbird wrote:

While it's all complex, I think you summarized the problem set pretty well, which is the more diverse you can make the soil, the better because all sorts of "minor" good things happen, and most bad things are diluted, so to speak.
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Danny D. wrote:

i've been studying soil sciences, gardening, microbiology, ecosystems, and many related topics for many years (agroecology, permaculture and regenerative agriculture are intersting topics :) ).
if anyone refers you to a university or agricultural school you will get the chem-ag approach to farming in mass production. many master gardeners programs use similar materials and philosophy and it is all through the gardening references and web-sites. it is often expensive and damaging in many ways. much more expensive than it needs to be.
songbird
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On Wed, 07 Sep 2016 10:32:44 -0700, Oren wrote:

I once drank from the Lehigh river, not too far from the Susquehanna (depends on what "far" means). I was hiking along the Appalachian, as I recall (it was very many years ago so I might have the details wrong) and I didn't get sick. I was shocked.
The water alone out there is good fertilizer!
(jk)
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On Wed, 07 Sep 2016 08:10:45 -0700, Oren wrote:

So it's an ugly carrot. I guess if it were being sold, it would matter. Thanks for edifying me.
I looked up ugly carrots, and found some pretty scary pictures!

Apparently it's 1/3 clay, 1/3 silt, and 1/3 sand.
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On 9/6/2016 5:41 AM, Danny D. wrote:

It's the fertilizer and the ability of the media to hold moisture that is important. After all you can grow plants hydroponically without soil. Get a good fertilizer from a gardening center. Tomatoes also like calcium and it pays to add limestone. I use regular cheap bagged topsoil in my pots.
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On Tue, 6 Sep 2016 07:59:56 -0400, Frank wrote:

It's more an experiment of how the local soil works, with a bit of fertilizer, if needed.
So my main question is how would I *know* if fertilizer is needed?
As for the ability to hold moisture, I think the water remains by capillary action, right?
Is there a *test* for that? I guess I could weigh a pot of the soil before and after watering, and then weight it a day or two later.
But is there a standard test for how soil holds moisture?
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On Tue, 06 Sep 2016 12:31:34 -0700, Oren wrote:

Out here, in California, except in the winter, the moisture has to be pretty low.
I looked at the first in your list: https://tinyurl.com/hfnmgmo
It was the DT-129 and it was just for wood (not soil). http://www.ecutool.com/DT-129-Moisture-Meter_7248.html
But it's too expensive to be practical ($166). It does seem to simply be a resistance meter though.
I'll bet most of the moisture meters are resistance meters.
Looking at the second one in your list, it's half that price: http://asungadget.com/shop/wheat-corn-paddy-rice-moisture-meter/
But it's a "Wheat corn paddy rice moisture meter" for testing grains. Still, it seems to be a resistance/conductance meter.
It gives a range of Moisture measurement range: 2%~30%
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On 9/6/2016 1:56 PM, Danny D. wrote:

My pots drain from the bottom into a pan and if there is water in the pan and roots deep than I add no water.
Fertilizer will be needed and I sorta determine how much by how growth is going. Too much all at once might kill the plant. In my opinion some potting soils that contain fertilizer have too much fertilizer to start plants in.
The calcium needed for tomatoes was discovered when I had blossom end rot and calcium cured it.
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