Should I have my soil tested?
A
soil test done by a commercial laboratory like A and L Soil
Testing Laboratory in Modesto, California, costs from $60-$75. It’s important
that a soil test is submitted to a soil testing laboratory that uses
appropriate testing. In other words, if you live in the desert don’t send it to
a soil testing laboratory that’s in a wet climate.
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| Sample Soil Test Report for Fruit Trees in the Desert |
Soil tests are mostly about what
fertilizers and soil amendments should be applied to get a desired yield. I was
in in the former Soviet Union years ago when a member of Parliament once asked
me, “What is the maximum wheat yield in the United States?” I told him, “US
farmers don’t maximize yields. They maximize profits.” Soil tests help farmers “maximize
their profits”.
Soil Chemistry
Soil tests are primarily aimed
at a “soil’s chemistry” to aid a famers profitability. Soil tests will not tell
you why a plant died, or chemicals added to the soil that killed a plant. An
agricultural soil test won’t tell you that. Those tests can be done, however,
but are much more expensive and requires a consultant to guide you.
How Often?
What good are soil tests to a
homeowner and when should they be done? A serious gardener should submit a soil
sample as soon as new property or growing area is purchased. A “first time”
soil test establishes a “baseline” and tells you at the beginning what’s
adequate about your soil chemistry and what’s missing. After that a soil test
is submitted by homeowners about every four or five years to make sure “they
are on track” with their fertilizer and soil amendment applications.
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| This is a soil test done by a homeowner. Garbage in, garbage out. I learned a long time ago to be careful sending soil samples in for analysis or doing it yourself. Luckily, this soil test matches what a desert soil sample report might look like. |
Soil Samples or Sample?
Soil tests are a smaller sample
of a larger soil sample taken from the top of the soil to the depth plant roots
grow. Several smaller samples representing this depth are added together. A
very clean five-gallon bucket is used for mixing the larger soil sample so that
a smaller sample, a pound or so, can be submitted for testing. Expect results
in about a week after they received your sample. If you’re having trouble
interpreting them, hire a consultant the first time so that you are taught how
to read them.