ABSTRACT
Silicon (Si) is the second most abundant element, both in terms of weight and number of atoms, in the earth’s crust. As silicon dioxides comprise more than 50% of soil, all plants rooting in soil contain Si in their tissues. However, the impact of Si on plant growth was hardly paid attention to for a long time. This inattention is because, unlike other nutrients, the symptoms of Si deciency are not easily observed visibly in plants. In 1862, Sachs, one of the early pioneers of plant nutrition, rst asked the following questions in his article on Si nutrition “…whether silicic acid is an indispensable substance for those plants that contain silica, whether it takes part in nutritional processes, and what is the relationship that exists between silicic acid and the life of the plant?” (Sachs, 1862). However, he could not nd benecial effects of Si on corn (Zea mays L.) growth. Nowadays, although Si has not been recognized as an essential element for plant growth, the benecial effects of Si have been observed in a wide variety of plant species.
