Types of eye twitching. Minor eyelid twitch also can be caused by irritation of the surface of the eye ( cornea) or the membranes lining the eyelids (conjunctiva). Sometimes the cause of minor eyelid twitch cannot be identified. In almost all cases it is painless and harmless.
Roots are not simply smooth, long structures. In fact, they typically have tiny hairs that cover most of the roots' length. These hairs absorb water and soluble nutrients for plant success. However, some critical nutrients, like phosphorus, are not readily absorbed by plant root hairs. Soil micro-organisms, such as earthworms, consume the surrounding elements and expel castings rich in soluble elements.
Nutrients take different forms (on a chemical level) depending on the pH around them. Some forms are easier for the roots to absorb than others. When the pH is too high or too low, the plant can show signs of a nutrient deficiency even when the nutrients are physically there at the roots.