2.
Put the words in alphabetical order.
i) road, dare, curiosity, important.
ii) modern, mail, mute, mingle
Answers
Advangates of using drip system of irrigation are :
It provides water to plants drop by drop.
Water is not wasted at all.
It can be used where availability of water is less.
Question 14.
Explain the manual method of removing weeds.
Solution:
The manual’removal of weeds includes physical removal of weeds by cutting them close to the ground from time to time. This is done with the help of khurpi or a harrow.
NCERT Solutions for Class 8 Science Chapter 1 – 5 Mark Questions and Answers
Question 1.
What are the two ways of sowing the seeds? [DAV2007]
Give any three advantages of ploughing.
Solution:
Seeds can be sown manually or by seed drills.
Ploughing has following advantages :
Loose soil has lot of air trapped which allows roots to breathe.
Loose soil allows the roots to penetrate deeper.
Loose soil helps the growth of microbes and other organisms.
Question 2.
What will happen if field is not ploughed before sowing the seeds? Give any two disadvantages. [DAV2006]
How are perishable food items stored on a commercial scale?
Why should excessive supply of water be avoided?
What are weeds?
Solution:
Disadvantages:
Seeds cannot be sown at proper depth.
Water and air holding capacity of soil will be poor.
Perishable food items can be stored in deep freezers and cold storages.
Roots get damaged and the plants die because of excessive supply of water.
They are unwanted plants which grow along with the cultivated plants.
Question 3.
(a) Why does farmer rotate crops in the field?
(b) Differentiate between manure and fertiliser. [DAV2005]
Solution:
(a) To replenish the nutrients of the soil.
(b)
Manure Fertiliser
(i) It is natural.
(ii) It is organic.
(iii) It adds humus to the soil.
i) Curiosity , Dare , Important , Road
ii) Mail , Mingle , Modern , Mute
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