History of Silicon
For years, silicon-based fertilizers have been overlooked in American agriculture and have been seen as a "not-needed, additional expense", but more recent research has shown that to be not so true.
For years, silicon-based fertilizers have been overlooked in American agriculture and have been seen as a "not-needed, additional expense", but more recent research has shown that to be not so true. Geologically speaking, the earth's crust contains approximately 31% silicon, 80% of the earth crust being a silicon-based compound. Naturally, silicon is around plants all the time and being readily absorbed by most plants in the form of silicic acid (H4SiO4) as observed from sampled soil:water solutions. However, this does not mean plants can readily uptake insoluble silicon. It must be converted from silicon (Si) to silica (SiO2) then to silicic acid (H4SiO4). This process either takes time through oxidation with constant exposure to water or needs processed by silicon-solubilizing bacteria to enzymatically convert insoluble silicon into its natural acidic form for proper uptake into the plant.
In 1814, scientist Sir Humphrey Davy spearheaded research on silicon supplements and their involvement in plant physiology writing, "The siliceous epidermis of the plant serves as support, protects the bark from the action of insects and seems to perform a part in the economy of these feeble vegetable tribes... similar to that performed in the animal kingdom by the shell of crustaceous insects." Essentially stating that the protective barrier on the plant, the siliceous epidermis, acts as a barrier to external pressures as the outer shell of insects protects the insects from environmental pressures.
Studies have shown that there are 3 types of plants regarding silicon: Silicon responsive plants that increase dry weight, Silicon accumulating plants that do not increase dry weight, and Silicon nonresponsive plants where silicon does not freely accumulate and translocate throughout the plant. Silicon responsive plants accumulate silicon into the cellular walls of the plant via the root system. Once accumulated, silicon translocates into the foliage and fruits of the crops depositing silicon into the tissue of the plant.
The dry weight increase of silicon responsive plants after applications of potassium silicate (K2SiO3) ranged anywhere from 6.0 - 80% depending on plant species. In controlled experiments, silicon concentration in plant shoots ranged from 39 to 700 ppm for control plants. Whereas, plants fertigated with silicon ranged anywhere from 74 to 1498 ppm of silicon, showing the drastic need for silicon-based fertilizer supplements.
Tissue analysis of foliage in plants have shown to range from 0.2% - 10% silicon concentrations in the dry weight of the plant. This concentration of Si in the plant is on par with the amount of calcium, magnesium, phosphorus, and sulfur, 4 essential elements in plants. This shows not only the importance of silicon-based fertilizers in the plants nutritional diet.