The potassium in the formula is absorbed by the plant.

The problem to be solved is how to recover said solution from the soil in a continuous and less expensive manner in order to allow automation of soil fertigation measurements and controls.

The root can take up magnesium exclusively in the form of Mg2+ dissolved in the soil solution.

Root absorption of plants is exclusively from potassium K+ dissolved in the soil solution.

Via the roots, crops only absorb calcium as Ca2+ dissolved in the soil solution.

The plant roots absorb this solution by osmosis, moving the less concentrated soil solution across their membrane to the more concentrated solution in the cells.

The soil heavy metal curing agent of the present invention can reduce the content of cadmium, lead, and mercury in a soil solution, and greatly reduce absorption of roots on these heavy metals.

In contrast, cations that are loosely bound or adsorbed to the negatively charged surfaces of soil particles do not move freely in soil solution.

A rise in pH diminishes the solubility of copper and the amount of Cu2+ in the soil solution.

As long as the concentration of the soil solution is lower than the salt concentration of the cell, the soil solution with its dissolved salts (fertilizer and minerals) will be carried into the cell and utilized.

The nitric form is completely released in the soil solution and preferentially feeds the plant.

Root absorption of plants is exclusively from potassium K+ dissolved in the soil solution.

Free salts are a mix of positive (cations) and negative (anions) ions that move freely in soil water, also known as the soil solution.

There is provided a sensor for measuring a quantity, such as the salinity, of the soil solution without requiring continuous calibration.

Boron is taken up by plants mainly in the form of boric acid.