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.