NCERT Class VIII Science Solutions: Chapter 1-Crop Production and Management Part 2

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Question 4:

Write a paragraph in your own words on each of the following.

  1. Preparation of soil

  2. Sowing

  3. Weeding

  4. Threshing

Answer:

  1. Preparation of soil:

  2. The preparation of soil is the first step before growing a crop. One of the most important tasks in agriculture is to turn the soil and loosen it. This allows the roots to penetrate deep into the soil. The loosened soil helps in the growth of earthworms and microbes which are friends of the farmer and add humus to it. Also, turning and loosening of soil brings the nutrient-rich soil to the top so that plants can use these nutrients.

As showing in images is a result for Preparation of soil

Result for Preparation of Soil

  1. Sowing:

  2. Sowing is the most important part of crop production. Before sowing, good quality seeds are selected. Good quality seeds are clean and healthy seeds of a good variety. Seeds can be sown by seed drill or manually.

As showing in images is a result for sowing

Result for Sowing

  1. Weeding:

  2. Weeds are unwanted plants that grown along with crops and removal of weeds is known as weeding. Weeds can be removed either manually by using tools like khurpi or by using weedicides like 2, 4 – D. These are sprayed in the fields to kill the weeds.

Images for Weeding

Weeding

  1. Threshing:

  2. The process of separation of the grains from the chaff is called threshing. This is carried out with the help of a machine called ‘combine’ which is in fact a combined harvester and thresher.

As showing in images is a result for Threshing:

Result for Threshing

Question 5:

Explain how fertilisers are different from manure.

Answer:

The main Differences between Fertilizer and Manure are as follows:

The Main Differences between Fertilizer and Manure Are as Follows
The main Differences between Fertilizer and Manure are as follows

S.No

Fertilizers

Manures

1.

A fertilizer is an inorganic salt.

Manure is a natural substance obtained by the decomposition of cattle dung, human waste and plant residues.

2.

A fertilizer is prepared in factories.

Manure can be prepared in the fields.

3.

A fertilizer does not provide any humus to the soil.

Manure provides a lot of humus to the soil.

4.

. Fertilisers are very rich in plant nutrients like nitrogen, phosphorus and potassium.

Manure is relatively less rich in plant nutrients.

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