Question

why fertilisers and manures increase soil fertility

Answer 1

Manures and fertilizers contain the essential nutrients which are present in low concentration in soil. Thus, increases the soil fertility and are good for crops. They add organic matter to the soil which may improve soil structure, aeration, soil moisture-holding capacity, and water infiltration. But these should not be used in excessive amount as it can leads to increase in the acidity of the soil. Secondly,fertiliser runoff from the fields also causes water pollution.