Agriculture Reference
In-Depth Information
Chapter 5
Soil Nutrient Testing
In 2006, I started an organic gardening service, one of the few in my city at the time that
were truly organic. This was my first chance to apply what I had learned from intensively
studying organic gardening to other people's gardens instead of just my own. I was mostly
quite successful, but had some problems dealing with weeds in some lawns, and the occa-
sional other pest. It took me a while to figure out that it was because I was neglecting to do
what is outlined in this chapter, and in later chapters on supplementing nutrients to balance
the nutrient ratios in the soil.
Most of my students and consulting clients have skipped this step, too, to the point
where I now say, “I know you're probably going to skip this step the first year, so all I ask
is that if things don't work for you like they should, you'll go ahead and get your soil tested
and then start to apply the appropriate fertilizers to balance the nutrients.” I understand the
hesitancy to go pay $50-$75 for a soil test, and then more money on the fertilizers. I know
many people don't want to do it, and the good news is it's possible to grow food with just
compost, so don't worry if you don't want to jump into this right away.
That being said, this is a topic on growing the most nutrient-dense food and plants pos-
sible, so it's definitely necessary to know. To me, this is crucial and it's what's missing in
most organic gardening topics that often focus more on organic matter and perhaps apply-
ing a few organic fertilizers, often fertilizers that can make things worse.
While talking to local farmers and soil experts can garner some useful information about
the most common soil deficiencies and excesses in your neighborhood, this information is
often not as useful in an urban setting. Many of our practices, or those of people who previ-
ously gardened our soil, can make the fertility in our back yard much different than our
neighbors. The soil may change when compost or topsoil has been brought in, pesticides
sprayed, chemical or mineral fertilizers applied. If you or someone else has applied dolo-
mite lime for 10 years in a row, that may have drastically changed the nutrient balance
from its original state.
To get better information about the soil, we need to do tests. The qualitative tests from
the last chapter are part of this, as is the brix test. We also do a couple of quantitative soil
tests. We want to do these different tests because if we make decisions based on only one,
