Do plants need silicon?

Abstract

Silicon (Si) may not be strictly considered an essential nutrient, but is accumulated by plants at macro-concentrations. Fertilization of various hydroponic and fiel-grown crops with Si has been shown to significantly increase herbage and reproductive yields, moderate the effects of some environmental stresses, and reduce the severity of some fungal diseases and pest attacks. Analysis of potting media and their substrates for plant available monosilicic acid suggests that they may be deficient in Si. Amending soilless media with soluble Si increases plant productivity and decreases severity of fungal diseases, but this may be moderated by other nutrient imbalances, resulting in loss of optimal productivity. Some options to amend media with Si are presented.