• Sources of Sulphur emit free sulphur, gaseous sulphur & H₂S in the atmosphere. Sulphur dioxide also produces from burning coal.
• These gases are dissolved in rain water & return to the soil and are poisonous to the living organism.
• If these gases are accumulated in soil in considerable quantity plants are unable to grow in such soil, similar cases may occur for aquatic organism. So, it is essential to remove H₂S from soil & aquatic habitat.
• Plants utilize sulphur in dissolved forms as sulphates. Leave also absorb SO₂ gas from the atmosphere. Sulphur exists as sulphates, parts of amino acids like lysine, methionine & in some substances e.g. Thiamine, Glutathione, Biotin etc. inside the plants.
• Plants do not use elemental sulphur. Sulphur passes through cycle of transformations mediated by microbes.

Sulphur accumulates in soil mainly as constituent of organic compounds & has to be converted into sulphates become readily available to the plants.