Actually, this should be
titled "Potash Fertilizers" since
commonly available only as a part of the compound with
oxygen called potash which has the chemical formula of K2O .
The way nutrients are
absorbed by plants is when they are in water solution.
So, the more soluble the nutrient, the easier it is to
move it into the plant. However, solubility also means
that the nutrient is likely to leach through the soil
faster also. Of the three nutrients commonly found in
is the most water
soluble, followed by potassium (potash) with
(phosphate) being the least soluble.
Each year, a moderate percentage of the
potassium applied will be
used during that season. For this reason, it may build
up over time. After several years of adding potassium to
the soil, you may find that you do not have to use any
for several years. Of course, you should periodically
take a soil test to determine the exact levels in your