Silica from steel mill slag plays a significant role in improving yields in a wide range of crops by increasing resistance to stress, strength and enhancing growth. Plants take up silicon into their root and shoot tissue, but it is not returned through biodegradation.
Silica is another word for Silicon and in plants, it is present in amounts equivalent to, or higher than, elements like Calcium, Magnesium or Phosphorus. Recent experiments show that plants deprived of Silica are structurally weaker, more prone to pest and disease attack, and are more susceptible to heavy metal and salt toxicities among other things. Once Silica is incorporated into a cell of a plant it is immobile and cannot be redistributed around the plant.