Silicon (Si) is one of the most abundant elements on Earth, found in large quantities in soil. While Si is not essential for land plants, many plants, such as rice and grasses, have used Si to develop powerful defense mechanisms against various environmental stresses. Silicon (Si) is one of the most abundant elements on Earth, found in large quantities in soil. While Si is not essential for land plants, many plants, such as rice and grasses, have used Si to develop powerful defense mechanisms against various environmental stresses. Molecular & Computational biology Agriculture Phys.org – latest science and technology news stories