Fertilisers

Question 1 What are fertilisers?

Question 2 Give few examples of fertilisers?

Question 3 What are the advantages of fertilisers?

Question 4 State the harmful effects caused by the excessive use of fertilisers?

Question 5 Give differences between manures and fertilisers?

• NCERT Solutions Class 8 Science

Fertilisers

A chemical fertiliser is a salt or an organic compound containing the necessary plant nutrient like nitrogen,phosphorus or potassium to make the soil more fertile.

For Ex:Urea,ammonium sulphate,superphosphate,potash,NPK.

Advantages of using Fertilisers

1)They provide quick replenishment of plant nutrients in the soil and restores soil fertility.

2)They are easily absorbed  by the plants.

3)They are easy to transport,store and handle because they come in bags.

4)The use of fertilisers has helped the farmers to get better yields of crops such as wheat,maize,rice.

Harmful effects of fertilisers

1)The excessive use of fertilisers changes the chemical nature of soil and makes the soil less fertile.

2)The excessive use of fertilisers causes water pollution in ponds,lakes and rivers.

Difference between Manures and Fertilisers

Manures	Fertilisers
It is a natural substance obtained by decomposition.	A chemical fertiliser is a salt or an organic compound
A manure is not very rich in essential plant nutrients.	Fertilisers are rich in plant nutrient like nitrogen, phosphorus or potassium.
A manure provide a lot of humus to the soil.	Fertiliser does not   provide any humus to the soil.
A manure is absorbed slowly by the plant .	They are easily absorbed  by the plants.
They can be prepared in the fields.	They are prepared in factories.