It’s really important to know what your
soil needs before you start a fertilizing program. Collect your soil,
send it to us and we’ll analyze it for you. Today we’re going to talk about this
type of soil testing, our soil analysis. This is part one of a series of two
videos today we’re going to talk about the terms and definitions found in your
soil analysis which will help you understand how to move forward. The
second video is going to talk about what amendments you should add if necessary
based on your results. Your soil analysis comes with a booklet called
understanding your soil analysis report. So get out your soil results and your
booklet and follow along. To learn how to understand the analysis at first glance,
your soil analysis results can look like a bunch of overwhelming numbers and
ratios on a graph but these numbers all relate to each other and should be
considered a whole when determining your soil needs. The first part to consider is
the chart of nutrient levels on this chart. You’ll see the amount of each of
the micro and macro nutrients as well as organic matter and if you opted for the
complete soil analysis, the trace minerals as well. The chart includes both
the concentration of each nutrient and a bar graph showing whether that value is
high or low. This chart is a large part of your soil
fertility puzzle but it’s not the whole picture. Just because you’re high or low
in a certain nutrient doesn’t mean that you have to go ahead and add that. There
are more things to consider. The second part is the percent cation (Cat-ion) saturation which shows the numerical percent of positively charged nutrients called
cations (Cat-ion’s) and also a bar graph of these numbers. The most common soil cations are potassium, magnesium, calcium and sodium. Ideally potassium will be four to seven
percent, magnesium ten to twenty percent, calcium sixty five to seventy five percent, and sodium less than three percent. The balance left will be the percentage of hydrogen which is
measured as pH. Because they’re a ratio, changing the values of one by adding fertilizer (for example) will have an effect on all of the other
values. So before adding anything take a few more things into consideration. For
example if your calcium is low in the first nutrient chart, adding high calcium
fertilizer will also raise its cation saturation percentage and lower the
percentages for the others, including raising your soil pH. The next thing to
consider is the ECE or the Electrical Conductivity of the soil and this is an
indicator of how much salts are present. In this set of data salts refer to more
than sodium as that is just one type of salt. There are other types of salts like
sodium chloride, magnesium, and calcium sulfates and bicarbonates. There are many reasons that soils become salty, including adding lots of manures
which are high in numerous kinds of salts, having a hard pan or poor drainage
that prevents salts from washing out of the soil and irrigating with water that
is high in minerals. ECE is considered high when the value is above 2.0. Hi ECE
will negatively affect crop yields. It restricts nutrient availability and soil
microorganisms. Cation exchange capacity or CEC is one of the more important
numbers on the report. This measures the ability of the soil to hold onto and use
nutrients that are present in the soil. Ideally this number would be 20 or
more. If it is lower it will improve over time as you improve the overall soil
health and quality. Good CEC is found where soil health is excellent and is
related to factors such as good microbial activity and organic matter
content. When looking at your nutrient levels and deciding how much fertilizer
to add, consider your CEC level. A good CEC will hold the nutrients in the soil
so your plants can use them over an extended period of time. It will also buffer your soil against changes in nutrients. So you will see a
slow delayed effect when trying to correct any imbalances. On the other hand, a low CEC soil cannot hold on to the nutrients when you fertilize.
Whatever your plants do not quickly use will be leached out of the soil, like
pouring fertilizers into a leaky bucket. To fertilize a low CEC soil, you’ll need
to add small amounts of fertilizer frequently instead of trying to fix your
nutrient levels all at once. Excess lime is usually not a problem but
if you have “H” in this box then you have high lime and it can be disastrous for
the health of your garden. You’ve been probably adding too much calcium
fertilizer if that’s the case. If you have an L it means it’s low and no
corrective action is required. Lime is usually added in the form of high
calcium fertilizers and high lime will also usually be reflected in a high
calcium nutrient level as well as an alkaline pH, which is a high pH. The pH
reading is probably the most misunderstood reading. pH indicates the
level of acidity or alkalinity in the soil. 7 is neutral, above 7 its alkaline
soil and below 7 its acidic soil. Most plants prefer a slightly acidic soil
between 6.0 and 6.8. Some such as blueberries and azaleas like it even
more acidic in the range of 4.1 to 5.0. Very few plants like a soil over 7.0
although some will tolerate it, such as Goji Berries. While a change from an
ideal 6.8 to a too alkaline 7.1 may not sound significant it is actually a large
jump in soil pH. It is not essential to get your pH exact because plants do have
a range that they can tolerate but your soil pH must be within this ideal range
for your plants to thrive. It will also harm the beneficial mycorrhizae and bacteria in the soil and encourage disease-causing organisms that thrive at
poor pH levels. If your soil pH is either too high or too low it’ll have a
negative effect on your plants. Even if the nutrients are in the soil, the plants
will not be able to take them up. If your soil pH is either too high or too low,
correct it very slowly over a long period of time. Going back and forth
between too acidic and too alkaline is worse for
your plants than doing nothing at all. Now that we understand all the terms and
definitions of the soil analysis report we can go on to step two, how to take
care of any problems we might have. So enjoy and grow organic for life.