Question

Biofertilizers are preferred over chemical fertilisers because

• A. They are cheap
• B. They do not cause pollution
• C. They are harmful
• D. None of the above

Answer 1

Answer: (B)

They do not cause pollution

Biofertiliser are preferred over chemical fertilisers because they contain organic materials while fertilisers contain chemical substances that when used in excess become harmful to the consumers. Continuous application of fertilisers to the soil decreases its fertility and also leads to increase in the acidity of the soil. Also the fertiliser runoff from the fields causes water pollution. Cyanobacteria such as Anabaena and Nostoc also fix atmospheric nitrogen and act as bio-fertilisers especially in paddy fields.

So the correct option is 'They do not cause pollution' .