Agriculture Reference
In-Depth Information
Ca
%
60-70
36.6
Mg
%
10-20
11.6
Na
%
0.5-3
0.2
CEC
mEq/100g
7.7
Note: The bold results show base saturations. This is the only part of
this soil test result that I really think is important.
On the previous page is an example of a test with some cations, anions and — the only
part I pay much attention to — the base saturations, in bold. Note that while it doesn't tell
me the hydrogen base saturation number, I can deduce that it's most of the remaining
49.4% because I know this is a base saturation test. I know the numbers have to add up to
100% and hydrogen is most of the remainder.
If you look at the parts that aren't bold, you may notice some inconsistencies. The num-
bers for calcium, magnesium and potassium aren't in the same ratios as they are in the
bold part. This may be because the units of measurement are different. I'm not sure. The
easiest way to get around it is to not look at the parts that aren't bold. The bold part is
what's important.
Looking at these results, we can see we have about a 3:1 calcium to magnesium ratio,
not at all uncommon and as we will see, probably not good. This soil and the plants in it
are going to have problems. Sodium is also low, as is the CEC. It's probably a fairly sandy
soil with this low CEC. We'll look at the next test to confirm this and get more detail.
