Agriculture Reference
In-Depth Information
Look at the Soil
The easiest test, and arguably the most important, is to spend just a little bit of time get-
ting acquainted with your soil firsthand. If you're like many people, reading about this kind
of stuff is more fun than doing it. It's easier for some of us to learn this than to put it into
practice. It took me a while to get into this because I'm a mathematical person who likes to
look at the numbers in a soil test, but playing in the dirt is a vital step I've come to cherish.
You need to actually go outside and do this to get any benefit from it. Find some kids to
help you. They love digging around in the soil for earthworms.
Dig a hole approximately 12 inches long, wide and deep. Try to take the soil out in big
chunks if possible and place it in a wheelbarrow or on a tarp. First of all, how easy is it to
dig? It should get easier every year as your organic matter content increases, your soil food
web grows and your nutrients get more balanced. Take note of how easy it is to dig, or rate
it on a scale of 1 to 10. That way, when you can stick your arm down into the soil up to
your elbow after 10 years, you'll remember where you started.
Look at the color of the soil. Dark brown is good. Pale beige, gray or blue is generally
not as good. Smell it, too. Soil should smell pretty nice. It definitely shouldn't smell bad,
like rotten eggs. Does it look like something you'd want to grow plants in?
You can use half a cup of soil to determine your soil texture — the relative amount of
sand, silt and clay in your soil. The sedimentation test from the previous chapter is my fa-
vorite, although you can judge just by manipulating some soil in your hand, as in the ribbon
test, also from the previous chapter. This information gives you a clue about the water and
air conditions in your soil. It also gives you a hint as to its ability to hold onto cations.
Look at the soil you've taken out and make some notes about its structure. It takes some
experience to do this, but it's really just a subjective, qualitative assessment of how your
soil looks. A good sign is if the soil particles are aggregating together in some way, rather
than staying separate like sand on the beach. You also don't want huge compacted clumps
of clay.
Another method of looking at structure comes from Graham Shepherd's
Visual Soil
Assessment
, a very good free guide for looking at your soil that you should download at
www.carbonfarming.org
because it has amazing photos to help you analyze your soil. Try
to dig an eight inch cube of topsoil and drop it a maximum of three times from waist height
into a bucket with a firm base, even with a piece of wood inside to help break up the cube.
Put the broken soil pieces and all of the fine soil from the bucket on a large plastic bag.
Some of the big clods will be cracked and you can break those apart at the cracks. Then or-
ganize your soil from big clods to small clods. The more fine soil and fewer clods you
have, the better. A good soil is mostly broken down into fines, whereas a poor soil stays
