Using Silicon as a Biostimulant
Silicon is the second most abundant chemical element in the Earth's crust. In the continental Earth's crust, that is the subsoil of lands used in agriculture, silicon is often associated with Oxygen. This association is called silica (SiO2). It composes many minerals in free form or combined form. If silica molecules are combined with each other, they become silicates[1].
Properties
Silicon (Si) is highly present in soils, in mineral inorganic form, in silicas and silicates. Plants assimilate this element in the form of organic silicon, also called silicic acid (H4SiO4). Although it is not part of the NPK triptych, research and practical experience show that this element is essential for the growth and development of many plant species, especially when they are exposed to abiotic or biotic stress.
Silicon is a non-essential mineral element whose benefits for plant growth have been widely demonstrated in several pot and field studies[2].
- The supply of silicon improves tolerance to certain abiotic stresses such as drought, salinity, or nutritional deficiencies.
- The presence of silicon in the soil promotes the absorption of phosphorus when phosphate fertilization is a limiting factor by increasing its uptake by the roots, and conversely the occurrence of chlorosis due to excess phosphorus is limited in the presence of Si thanks to a decrease in P absorption[2].
- Also, the absorption of K, N, and Ca is improved even with a low supply of Si, which promotes better growth of crops[2].
- Finally, in case of water deficit, foliar application of Si improves the relative water content in plants by enhancing exchanges through stomata and limiting water loss by transpiration.
- Moreover, silica improves the antioxidant activity of enzymes and stabilizes cellular structures[2].
- Overall, silica helps to slow down the overall senescence process of plants.
Modes of action
Beyond these observations, the modes of action of silicon remain poorly understood; here are the avenues raised during various scientific researches :
- Silicon would deposit in the plant tissues and provide them with mechanical resistance and elasticity. This property would also influence the mobility of nutrients and water within plants.
- Silicon would stimulate the plant antioxidant system. This system prevents damage to cell components such as DNA.
- Silicon would promote the establishment of better cell signaling, complex mechanisms allowing cells to coordinate their activities and to be able to respond properly to their micro-environment. This improvement would be observed through phytohormones, although evidence of a direct involvement of silicon in this process is currently lacking.
La technique est complémentaire des techniques suivantes
- ↑ Académie des biostimulants, online, INORGANIC BIOSTIMULANTS : The example of Silicon
- ↑ 2.0 2.1 2.2 2.3 Guntzer, F., Keller, C. & Meunier, J.-D., 2011. Benefits of plant silicon for crops: a review. Agronomy for Sustainable Development, 32(1).
