Water management addendum:

Salts

As gardeners and horticulturists, we talk about salts the way the chemists do
we are talking about a crystalline solid formed by a positive and a negative ion

table salt is sodium chloride, nice clear white crystals sitting in a shaker jar
pour that salt into water and the bonds split
the salt dissolves into solution
sodium and chloride become ions swishing and swashing around,
tucked within the H2O
sodium ion is charge positive +
chloride ion is charge negative –

an ion, by the way, is an electrically charged particle
the particle can consist of just one atom,
or it can consist of a group of atoms – polyatomic, a molecule
for example, sodium chloride is one atom of sodium to one atom of chloride
if the salt was ammonium nitrate, that would be one ion of ammonium and one ion of nitrate
ammonium is NH4 (one nitrogen and four hydrogens)
while nitrate is NO3 (one nitrogen and 3 oxygens)

we can now call that water solution full of ions an electrolyte,
meaning it conducts electricity
kinda the same concept as a car battery
or the special vitamin water or sports drink that says it replenishes your electrolytes
or the cells in your body with sodium and potassium coming in and out all the time
we are all skin bags of water, filled with bits of charged ions

now go look on any fertilizer or potting mix label


ammonium nitrate salt
ammonium ion is positive, nitrate is negative, easy

potassium phosphate salt
Potassium is positive, phosphate is negative, easy

calcium nitrate salt
calcium is positive, nitrate is negative, easy

potassium sulfate salt
potassium is positive, sulfate is negative, easy

all those -ates: sulfate nitrate phosphate
theres gotta be a pattern
yeah it just means theres some oxygen in there cause oxygen loves to bind with others
sulfur and oxygen – sulfate
nitrogen and oxygen – nitrate
phosphorus and oxygen – phosphate

if you are ground water running through limestone channels or quarries
for sure you will pick up some of that calcium and magnesium in the limestone
then that water is called ‘hard’, and it forms deposits on the kettles and things called ‘scale’

if you are ground water running through sodium rich soils
then you will pick that up too
and become sodic or saline or salty
maybe somebody will put you in a pond, and evaporate the water
then bag that salt and sell it to passerbys and traveling caravans

if you are rain water, that is pretty pure stuff for the most part
unless you picked up some burnt stuff particles on the way down from the clouds
some bits of sulfur or nitrogen from the volcano or the power plant…

in general
as a gardener and nursery person, you want minimize the salt buildup in the soil
a little bit of salts (fertilizers) is good right?
yes, but you want a balance, you want just enough, not too much of a good thing
which becomes a bad thing

imagine you have the soil chock full of sodium ions
and the plant stops absorbing the other ions altogether
no more magnesium and calcium and iron and copper and potassium and zinc
all it gets is sodium
not good, gonna get sick
plant goes caput, and your career as a grower goes down down down

time to time you may have to leach the soil, or add other things to compensate & balance for
the distribution and quantity of ions
the amount of salts

last thing
just to be technical and make the high school chemistry teachers happy
a negative ion is called an anion
and a positive ion is called a cation, a ca+ion