If the roots get “drowned”, the plant is going to die!

Objective: To show that the roots of the plants need air for respiration.

Materials required: Two potted plants such as balsam, rose, sunflower etc. that are similar in size, some wet clay or some plastic putty.

Procedure: Take two potted plants A and B. Block the hole at the bottom of one of the pots (pot-B) using wet clay or plastic putty. Leave the plants in open space where there is sufficient sunshine. Water the plants twice a day. Continue this experiment for two weeks or more.

Observe the pots everyday for the following: (i) Absorption of water into the soil, whether it seeps down or stays.
(ii) Whether the leaves stay firm or wilt/droop. Record your observations. What happens to the plant in pot-A? What happens to the plant in pot-B?

Interpretation: Excess of water that fails to drain out from pot-B (with the bottom hole blocked) drives out air from the soil. As a result the plant roots do not get oxygen for respiration and so the leaves of the plant will wither and ultimately die.