Thread: Testing Soil

I would like to do an experiment, sampling the soil in different areas for their properties just to have a better understanding of soil.

I don't know how yet, but I want to test for pH and mineral content. Is there anything else that I should test for? I was thinking of checking for number of worms and other critters, and keeping track of debris.

I am mostly curious about testing the soil where different things grow

A grassy field: I will test the higher dryer areas, and the lower wetter areas
Underneath Apple Trees: Obviously it will be very acidic, but I want to know exactly how acidic.
In the woods: Near trees where the branches fall and rot, and also away from the trees where not so many do.
Brambles: I want to know what sort of soil they grow in and what soil they don't to see what I can change to get rid of them or make them spread where I want them.

I don't know what to expect.

If anyone wants to do the same thing where they live, we could compare data, it might be interesting.

I don't have a lot of formal understanding here either, but some things I would take count of:

Particle size. Sand is very large. Planting soil is probably very small, or made of decaying pant bits that form more of a web than particles.

Color.

Smell. Obviously a bit subjective, just write down what it reminds you of. Like this reminds me of the air after a rain storm in spring. This reminds me of the sea. This has no discernible odor. Etc.

Definitely try to determine pH.

Definitely try to count bugs and the like.

Definitely take several samples per site.

If you have access to a pharmacutical type scale (one which can accurately measure in the hundredths of grams) try determining particulates by mass. Like 20% by mass is what I think are decaying plant products. 50% by mass is coarse grained sand, etc. etc.

Originally Posted by Numsgil

If you have access to a pharmacutical type scale (one which can accurately measure in the hundredths of grams) try determining particulates by mass. Like 20% by mass is what I think are decaying plant products. 50% by mass is coarse grained sand, etc. etc.

Another simple test will tell you the percent by volume. Couple scopes of soil into a jar up to say 1/3 full; add water; mix it thoroughly so even smallest particles separate and set on a shelf for a day or so. The settling does a pretty good job of sorting out the sand (bottom) from the clays by density into layers. Measure the thickness of the layers to get an idea of % by volume.

Originally Posted by marcusclayman

I would like to do an experiment, sampling the soil in different areas for their properties just to have a better understanding of soil.

I don't know how yet, but I want to test for pH and mineral content. Is there anything else that I should test for? I was thinking of checking for number of worms and other critters, and keeping track of debris.

I am mostly curious about testing the soil where different things grow

A grassy field: I will test the higher dryer areas, and the lower wetter areas
Underneath Apple Trees: Obviously it will be very acidic, but I want to know exactly how acidic.
In the woods: Near trees where the branches fall and rot, and also away from the trees where not so many do.
Brambles: I want to know what sort of soil they grow in and what soil they don't to see what I can change to get rid of them or make them spread where I want them.

I don't know what to expect.

If anyone wants to do the same thing where they live, we could compare data, it might be interesting.

Iron and or rust, verses carbon would be one I would be interested in. I suspect that high carbon soils out produce high iron soils, for a lot of different crops. Or it may just be higher carbon, masks the same amount of iron present.

It may just be carbons ability to hold a lot of water and chemicals that allows it to help plants grow. There is a huge amount of square feet, per gram of activated carbon. Something like ten square feet per gram. But that is from memory, and sometimes my memory is not that good. I do remember it was a huge amount of square feet.

My grandfather and grandmother made a mean humus out of mostly coffee grinds. Wow did stuff grow in it. Often at a rate many times faster then regular soil, by actual testing. Some stuff that grew in the humus would not even grow in regular soil.

Sincerely,


William McCormick

Originally Posted by William McCormick

There is a huge amount of square feet, per gram of activated carbon. Something like ten square feet per gram.

What does this mean?

It's a while since I've done this, so forgive me for any omissions.

You should be interested in:
-pH: get a pH meter, litmus paper etc.

-Organic matter content: The way to test this is called Loss on ignition. You measure out an amount of soil, let it dry out thoroughly in an oven set to a touch over 100. This will probably take a few hours. Weigh it. The organic matter will have to now be burned off. Normally this will be done in one hell of an oven, the likes of which you won't find in any kitchen. I think it's supposed to be at over 1000c. I guess you'll have to improvise here involving fire somehow. The weight of material remaining minus the weight of dry matter is your weight of organic material.

-Grain size: Normally decribed as amounts of sand, silt and clay. The most accurate way to tell would be to pass a known amount through nested sieves of different sizes and weigh what you get in each one. Grains will be stuck together though. I forget what the normal way to separate is, but I'd go with rinsing water through the sieves and dispersing them with a soft brush, then dry and weigh what's in them. You can also do much more simple estimates based on how a damp sample feels, how easy it is to mould, roll in to balls... I forget the specifics of this but there will be keys you can work for somewhere. Knowing the amounts, you can assign your soil a place here: http://www.soilsensor.com/images/soiltriangle_large.jpg

- Structure: Soil will aggregate together to form peds- from tiny crum-like things to tall well compacted prisms

-Profile: Dig a pit and you'll see that is separated in to layers called horizons. The depth and caracteristics of each of these layers will be important.


This is by no means an exhaustive list. I know I'll have missed a lot. You should probably try to get yourself a soil science textbook and have a good read.

Originally Posted by marcusclayman

Originally Posted by William McCormick

There is a huge amount of square feet, per gram of activated carbon. Something like ten square feet per gram.

What does this mean?

It means my memory is failing, ha-ha, there is actually 10,000 square feet of surface area inside a gram of activated charcoal. That means that it can either hold tiny bits of nutrients for plants. Or it can absorb powerful toxins that might hurt plants. Or both.

Activated charcoal is a highly overlooked substance.

It has a specific gravity of around .08 to .5 that means that it is very light, and does not compact well. Allowing for water to pass through and around it very well, especially good for roots.

I think this substance in plant growth is highly overlooked.

Sincerely,


William McCormick

Yup. Check out the biochar thread.

You might find a soil testiing kit in the local garden supply store, but those are rather useless. They are supposed to test for pH, nitrogen, phosphorus and potassium I think - the ingredients of fertilizer. I tried to use one of those kits once and didn't have much luck. I think you would be better off taking your samples to the county agricultural agency who will charge a small fee for it.

Originally Posted by Kukhri

Yup. Check out the biochar thread.

That was a good thread. You are right about that stuff. I saw what it could do for crop production first hand. Amazing. We would not need Canada for our food production here in America, with that stuff.

http://en.wikipedia.org/wiki/Humus

This is basically what I used to make, and use with my Grandfather. He grew evergreen trees and bushes, from cuttings. Wow did they grow fast in this stuff. It is pitch black if made right. And it is so light to work with. Even wet or damp it was not heavy.

Coffee grinds are the secret. You could reclaim them from every 7-11, and Deli across the world.


Sincerely,


William McCormick

Thanks for all the info guys. I'm dumb, I know what you mean now, for some reason I thought you were talking about volume and thought the square foot thing was a typo. Here I am trying to sound smart, haha.

I'm following all the links for "Biochar" now, thanks again, real interesting

something about Terra Pretta though, however you spell it. The "black earth" of the ancient amazons. I don't know, but I remember hearing something about it, and I thought it was mentioned that we have never been able to replicate it. I will look it up, but does anyone know anything about it?

Since your name includes the word 'clay' you should run a methylene blue test which will give you the cation exchange capacity of your sample. That is related to the amount of charge imbalanced clay, such as montmorillonite, that you have in the sample.

Originally Posted by marcusclayman

Thanks for all the info guys. I'm dumb, I know what you mean now, for some reason I thought you were talking about volume and thought the square foot thing was a typo. Here I am trying to sound smart, haha.

I'm following all the links for "Biochar" now, thanks again, real interesting

something about Terra Pretta though, however you spell it. The "black earth" of the ancient amazons. I don't know, but I remember hearing something about it, and I thought it was mentioned that we have never been able to replicate it. I will look it up, but does anyone know anything about it?

Coffee grinds, egg shells, food. Stuff like that. Not to much paper. But sometimes some paper would get in. You just have to make it and turn it two or three times a day.

It was kept in a wooden container above ground. So it could leach. It stays wet enough like that.

It is like making sour dough, once you have the culture, you just take and add small amounts. Keeping the main mix, working. It is magic.


There were companies that made a machine to turn it with a crank. A neighbor of mine had one years ago.




Sincerely,


William McCormick