Silicon: nutrition and fertilization in higher plants

Abstract

In this study, we aimed to provide information about the use of silicates in plant cultivation. Although silicon (Si) is one of the most abundant elements found in most soils in substantial quantities, various classes of soils, mainly the sandy ones, present low amounts of available Si in their upper horizons. In these soils, some plants such as sugarcane and rice, which have keen ability to accumulate Si in their tissues, can respond favorably to silicon fertilization. Silicates behave similarly to calcium and magnesium carbonates in soil, promoting chemical reactions similar to those induced by limestone, including pH increase, precipitation of toxic aluminum (Al3+) and manganese (Mn2+), increase of exchangeable calcium and magnesium and base saturation levels, and reduction of Al3+ saturation, with the additional benefit of increasing Si levels in soils. Si benefits to plants are related mainly with increasing their resistance to attacks by insect pests, nematodes and diseases, and with reducing their transpiration rate, which provides further tolerance to water stress during periods of low soil moisture.