If Farmers grow crop again and again in same field,what will happen?
Plants and Crops require nutrients to grow,
If we grow crop again and again in same field, soil will become poor in nutrients.
So we need to add Manures and Fertilizers to add nutrients in the soil so that plants can grow properly,
What are Manures and Fertilizers?
Manures
They are natural substance.
They are obtained by decomposition of plants and animal wastes
This decomposition is done by microorganisms.
Steps
Farmers store plants and animal waste in pits
These are decomposed in few days by microorganisms
This decomposed matter is added in soil
This gives essential nutrients to soil and make soil fertile.
Fertilizers
They are prepared in factories(They are manmade,not natural)
They are rich in particular nutrient like Urea,ammonium,sulphate,phosphate etc
What are harmful effects of using fertilizers?
Too much use of fertilizers make soil infertile
They lead to water pollution
What is the Difference between Manures and Fertilizers?
What are Advantages of Manures over Fertilizers?
It increase water holding capacity of soil(soil is able to retain more water)
Soil becomes porous(gases are able to pass through soil)
It helps in growth of friendly microorganisms(microbes)
it improves texture of soil
It does not cause water pollution like fertilizers
What is Crop Rotation?
It is a agriculture practice in which
Different types of crops are grown alternatively in same fied or soil
Example
In North India,Legumes(Plants having pods like peas,beans) are grown in one season and Wheat is grown in other season
Why is Crop Rotation Done?
It helps in replenishing soil with nutrients (adding nutrients to soil)
Examples Rhizobium bacteria present in the nodules of roots of leguminous plants helps in fixing atmospheric nitrogen.
Less Nitrogenous Fertilizer is required to be added to the soil(as it is provided by legumes)
Questions
NCERT Question 2 - Match items in column A with those in column B
|
A |
B |
|
(i) Kharif crops |
(a) Food for cattle |
|
(ii) Rabi crops |
(b) Urea and superphosphate |
|
(iii) Chemical fertilisers |
(c) Animal excreta, cow dung urine and plant waste |
|
(iv) Organic manure |
(d) Wheat, gram, pea |
|
(e) Paddy and maize |
NCERT Question 5 - Explain how fertilisers are different from manure:-
NCERT Question 8 - Explain how soil gets affected by the continuous plantation of crops in a field.
