Active Transport in Plant.
One example is Calcium ions.
Diffusion 
The soil water around
the root hair have higher concentration of calcium ion as compared
to hair. Therefore, it will diffuse into the root hair cell.
Active Transport Root hair cell can
still absorb Calcium ions even when the amount of Ca ions in the
Root hair is higher than the surronding soil water
Calcium ions are absorb into the root hair cell which are against
the concentration gradient. Meaning absorbing from Higher concentration to lower
concentration.
Since it's against the concentration gradient, it require energy to
carry out this process.
