Why are manure and fertilizers used in fields ?

What are 'manures' and 'fertilizers' ?

For what purposes the chemical fertilizers are used in crop fields ?

Compare the use of manure and fertilizers in maintaining soil fertility.

Compare the use of manures and fertilizers in maintaining soil fertility.

Why do farmers spread fertilisers and manures in the fields ?

Assertion : Manures and biofertilizers shuld be used in place of chemical fertilizers. Reason : Chemical fertilizers cause pollution by releasing excess nutrients in water bodies.

Why are manures used in bulk to increase soil fertility ?

A farmer is growing a crop regularly in his field. He uses chemical fertilizers, pesticides, organic manure as well as bio-fertilizers. Very close to his field is a factory which emits smoke as a by product. There is also a huge lake in the nearby area. An expert agriculturist suggests to the farmer to minimize the use of chemical fertilizers and instead use biofertilizers as they have many advantages over chemical fertilizers. Which of the following is NOT true for biofertilizers?