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Page No 14:

Question 1:

Drip irrigation is used in places where
(a) there is plenty of water available.
(b) there is little water available.
(c) the water table is very low.
(d) the water needs to be lifted up.

Answer:

(b) there is little water available.
Drip irrigation is used in places where there is little water available.

Page No 14:

Question 2:

Which one of the following is not an example of a kharif crop?
(a) maize
(b) rice
(c) mustard
(d) pulses

Answer:

(d) pulses

Pulses are rabi crops.



Page No 15:

Question 3:

Separation of grains from the chaff is called
(a) winnowing.
(b) harvesting.
(c) separation.
(d) threshing.

Answer:

(a) winnowing

Separation of the chaff from the whole grains is called winnowing.

Page No 15:

Question 4:

Before sowing, the first step in the cultivation of crops is
(a) removing the weeds.
(b) watering the field.
(c) preparing the soil.
(d) levelling the soil.

Answer:

(c) preparing the soil
The first step in the cultivation of crops is preparing the soil.

Page No 15:

Question 5:

A crop that enriches the soil with nitrogen is
(a) wheat.
(b) mustard.
(c) carrot.
(d) beans.

Answer:

(d) beans
Beans are legumes; Their root nodules have nitrogen-fixing bacteria. Therefore, they help in  enriching the soil with nitrogen.

Page No 15:

Question 6:

Atmospheric nitrogen is fixed by __________.
(a) lightning
(b) blue-green algae
(c) bacteria present in the root nodules of leguminous plants
(d) all the above

Answer:

(d) all the above
Atmospheric nitrogen is fixed by all the given factors.

Page No 15:

Question 7:

Crop rotation is the method by which
A. crops are rotated to 90 degrees.
B. cereal crops are alternated with legumes.
C. crops are grown separately.
D. soil is enriched with nitrogen.

(a) Only B is correct
(b) B and C are correct
(c) B and D are correct
(d) All are correct

Answer:

(c) B and D are correct

In crop rotation, legumes are grown alternately with cereal crops for enriching the soil with nitrogen.

Page No 15:

Question 8:

Basin irrigation is done in
(a) wheat.
(b) rice.
(c) maize.
(d) vegetables.

Answer:

(b) rice

Basin irrigation is suitable for rice crops, where the fields are flooded with water.

Page No 15:

Question 9:

Furrow irrigation is not done in
(a) vegetables.
(b) banana.
(c) wheat.
(d) rice.

Answer:

(c) banana

Furrow irrigation is suitable in the cultivation of wheat, vegetables and other crops. It is not done in banana.

Page No 15:

Question 10:

Manures are not made of
(a) cow dung.
(b) farmyard waste.
(c) urea.
(d) leaves.

Answer:

(c) urea
Manures are not made of urea.

Page No 15:

Question 11:

An example of a mixed fertiliser is
(a) urea.
(b) CAN.
(c) KNO3.
(d) K2SO4.

Answer:

(b) CAN

CAN supplies the soil with calcium, ammonium and nitrogen. It is an example of a mixed fertiliser.

Page No 15:

Question 12:

Which implement is not used for removing weeds?
(a) tractor
(b) Japanese weeder
(c) trowel
(d) harrow

Answer:

(a) tractor

A tractor is used for driving a harrow.

Page No 15:

Question 13:

List two differences between manure and fertilisers.

Answer:

Manure Fertiliser
It is a natural substance obtained by decomposition of animal wastes and plant residues. It is a man-made substance, generally an inorganic salt or an organic compound.
It is rich in organic matter and adds humus to the soil. It is rich in inorganic matter and does not contain humus.

Page No 15:

Question 14:

Give one advantage and one disadvantage of fertilisers.

Answer:

Advantage of fertilisers:
They provide specific nutrients that are not present in the soil.

Disadvantage of fertiliser:
Excess use of fertilisers damages the soil by making it too acidic or too alkaline.

Page No 15:

Question 15:

Write short notes on the following:
hybridisation, irrigation, integrated farming, crop protection, symbiotic nitrogen fixation

Answer:

Hybridization: The crossing two varieties of crops having different characteristics to produce a variety with desired characters, is known as hybridisation. This process is continued till the desired characters are obtained.

Irrigation: The watering of fields is known as irrigation. Water for irrigation is drawn from wells, tube wells, ponds, rivers and canals. 

Integrated farming: Dairy and poultry farming can be combined with fisheries so that the waste products of the former can be used to feed the fishes. This process is called integrated farming.

Crop protection: Crops need to be protected from pests such as, rats, mice, insects, birds, and microorganisms such as, bacteria, virus and fungi. Pesticides or chemicals are sprayed on plants for their protection from these pests.

Symbiotic nitrogen-fixation: Bacteria live in the root nodules of leguminous plants. They fix the atmospheric nitrogen and convert them into usable form for the plants. In return, they receive nutrients from the plants. This process is known as symbiotic nitrogen fixation.

Page No 15:

Question 16:

Classify the following crops according to their use.
maize, pepper, pea, mustard, sugarcane, clove, potato, banana, coffee

Answer:

Maize- Cereal crop

Pepper, clove- Spices

Pea- Pulse

Mustard- Oil seeds

Sugarcane- Sugar crop

Potato- Vegetable

Banana- Fruit

Coffee- Beverage

Page No 15:

Question 17:

How is tillage or ploughing helpful to crops?

Answer:

Ploughing or tillage is helpful to crops in the following ways:
1) It allows air to enter the soil. This in turn helps the roots of the plants to breathe.
2) This air is also needed by the microorganisms present in the soil to carry out the decomposition of organic matter which adds nutrients to the soil.
3) Unwanted plants gets uprooted.
4) Pests are exposed and consequently, killed by predators or the heat of the Sun.



Page No 16:

Question 18:

Differentiate between basin irrigation and furrow irrigation.

Answer:

Basin Irrigation Furrow Irrigation
In this type of irrigation, fields are flooded with water. In this type of irrigation, water is channelled into furrows.
It is used in rice fields. It is used in wheat and vegetable fields.

Page No 16:

Question 19:

Name some common pests of plants and mention how they can be controlled.

Answer:

Some common pests of plants are rats, mice, insects, birds etc.

Birds can be scared off by beating drums or by using scarecrows. Other pests can be controlled by using pesticides like DDT, BHC and malathion or by using chemicals like pheromones.

Page No 16:

Question 20:

List the various agricultural practices followed by farmers to ensure that they have a plentiful, healthy crop.

Answer:

The various agricultural practices followed by farmers to ensure that they have a plentiful, healthy crop are as follows:
1) Preparing the soil
2) Sowing the seeds
3) Irrigation
4) Using manure and fertilisers
5) Weeding
6) Protecting the plants against pests and diseases

Page No 16:

Question 21:

Give one use each of the following:
harrow, sickle, trowel, soil plank, leveller, fungicide, combine, silo

Answer:

Harrow: It is used for removing weeds in large fields.

Sickle: It is used to cut down crops.

Trowel: It is used to remove weeds by hand.

Soil plank: It is used for breaking down soil into small pieces.

Leveller: It is used to press down and level the land.

Fungicide: It is used to control fungus in plants.

Combine: It is used to harvest the crops and separate them from the chaff in large farms.

Silo: It is used for large scale storage of crops.

Page No 16:

Question 22:

What are weeds? Why should they be removed?

Answer:

The unwanted plants that grow in the fields along with crop plants are known as weeds.
They should be removed because they compete with the crop plants for space, light, minerals and nutrients, thereby increasing the competition for these crops. Presence of weeds leads to a drop in yield.

Page No 16:

Question 23:

What will happen if we keep on growing crop after crop without using manure or fertilisers?

Answer:

If we keep on growing crop after crop without using manure or fertilisers, the nutrients in the soil would get depleted. The crops planted in such fields would be weak and the yield would progressively deplete.



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