Exercises
Question 1
Select the correct word from the following list and fill in the blanks.
| float, water, crop, nutrients, preparation |
|---|
(a) The same kind of plants grown and cultivated on a large scale at a place is called ............... .
(b) The first step before growing crops is ............... of the soil.
(c) Damaged seeds would ............... on top of water.
(d) For growing a crop, sufficient sunlight and ............... and ............... from the soil are essential.
Answer
(a) The same kind of plants grown and cultivated on a large scale at a place is called crop .
(b) The first step before growing crops is preparation of the soil.
(c) Damaged seeds would float on top of water.
(d) For growing a crop, sufficient sunlight and water and nutrients from the soil are essential.
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 super phosphate |
| (iii) Chemical fertilisers | (c) Animal excreta, cow dung urine and plant waste |
| (iv) Organic manure | (d) Wheat, gram, pea |
| (e) Paddy and maize |
Answer
| A | B |
|---|---|
| (i) Kharif crops | (e) Paddy and maize |
| (ii) Rabi crops | (d) Wheat, gram, pea |
| (iii) Chemical fertilisers | (b) Urea and super phosphate |
| (iv) Organic manure | (c) Animal excreta, cow dung urine and plant waste |
Question 3
Give two examples of each.
(a) Kharif crop
(b) Rabi crop
Answer
(a) Kharif crop: Cotton, Soyabean
(b) Rabi crop: Wheat, Mustard
Question 4
Write a paragraph in your own words on each of the following.
(a) Preparation of soil
(b) Sowing
(c) Weeding
(d) Threshing
Answer
(a) Preparation of soil — Preparation of soil is primary step before growing a crop. It involves loosening and turning of soil. The process of loosening and turning of the soil is called tilling or ploughing. Turning the soil and loosening it allows the roots to penetrate deep into the soil. The loose soil allows the roots to breathe easily even when they go deep into the soil. The loosened soil helps in the growth of earthworms and microbes present in the soil. Since only a few centimetres of the top layer of soil supports plant growth, turning and loosening of soil brings the nutrient-rich soil to the top so that plants can use these nutrients.
(b) Sowing — Sowing of seeds is done after ploughing of land. Before sowing, good quality, clean and healthy seeds of a good variety are selected and are put into water. The floating seeds are rejected as they are damaged or hollow. Seeds are either broadcasted by hand or are sown with the help of traditional tool with a funnel. Nowadays the seed drill is used for sowing with the help of tractors. This sows the seeds uniformly at equal distance and depth. It ensures that seeds get covered by the soil after sowing. This protects seeds from being eaten by birds. Sowing by using a seed drill saves time and labour.
(c) Weeding — Undesirable plants growing naturally along with the crop are called weeds. The removal of weeds is called weeding. Weeding is necessary since weeds compete with the crop plants for water, nutrients, space and light. Thus, they have adverse effect on the growth of the crop. Weed management can be done by following ways:
- tilling before sowing uproots and dries weeds.
- manual removal with help of khurpi.
- by using chemicals, known as weedicides. For example, 2,4-D
(d) Threshing — The process of separation of the grains from the chaff is called threshing. The primary goal of threshing is to extract the edible part of the plant, which is the grain or seed, from the non-edible parts. It is done with the help of threshing machine or combine. A combine is a harvester as well as a thresher.
Question 5
Explain how fertilisers are different from manure.
Answer
| Fertilisers | Manure |
|---|---|
| Fertiliser is a man-made inorganic salt. | Manure is a natural substance obtained by the decomposition of cattle dung and plant residues. |
| Fertiliser is prepared in factories. | Manure can be prepared in the fields. |
| Fertiliser does not provide any humus to the soil. | Manure provides a lot of humus to the soil. |
| Fertilisers are very rich in plant nutrients like nitrogen, phosphorus and potassium. | Manure is relatively less rich in plant nutrients. |
| Fertilisers are not good for soil as they degrade the soil in long run. | Manures improve the soil texture. |
| They cause water pollution. | They do not cause water pollution. |
Question 6
What is irrigation? Describe two methods of irrigation which conserve water.
Answer
The supply of water to crops at regular intervals is called irrigation. The two methods of irrigation which conserve water are:
- Sprinkler System — This system is useful on the uneven land where sufficient water is not available. The perpendicular pipes, having rotating nozzles on top, are joined to the main pipeline at regular intervals. When water is allowed to flow through the main pipe under pressure with the help of a pump, it escapes from the rotating nozzles. It gets sprinkled on the crop as if it is raining. Sprinkler is very useful for lawns, coffee plantation and several other crops
- Drip system — It is more efficient than sprinkler system. The water is taken to plants through a pipe and water is given to plants drop by drop near their root. It is the best technique for watering fruit plants, gardens and trees. Water is not wasted at all. It is a boon in regions where availability of water is poor.
Question 7
If wheat is sown in the kharif season, what would happen? Discuss.
Answer
If wheat is sown in the kharif season, most of the seeds would not germinate. Few germinated seeds will not grow and form grains because the wheat crop requires less water and low temperature for growth, flowering and grain formation. In kharif season, temperature is high and frequent rain spells provide lot of water.
Question 8
Explain how soil gets affected by the continuous plantation of crops in a field.
Answer
The continuous plantation of crops in a field depletes the soil of nutrients essential for plant growth. When the same type of crop is grown repeatedly, it exhausts specific nutrients from the soil that are crucial for that particular plant's development. We need to follow crop rotation and nutrient management to address this issue. Adding manure and appropriate amount of fertilizers can maintain the soil texture as well as nutrients.
Question 9
What are weeds? How can we control them?
Answer
Weeds are undesirable plants that grow along with the main crop. Weeds can be controlled by following methods:
- Tilling before sowing of crops helps in uprooting and killing of weeds
- Weeds can be manually removed with the help of khurpi by uprooting or cutting them close to the ground.
- Weeds should be removed before their flowering because they produce seeds in large number which are easily dispersed by wind.
- Weeds are also controlled by using certain chemicals, called weedicides, like 2,4-D. These are sprayed in the fields to kill the weeds. They do not damage the crops.
Question 10
Arrange the following boxes in proper order to make a flow chart of sugarcane crop production.
Answer
Flow chart of sugarcane crop production by arranging the boxes in proper order is shown below:
Question 11
Complete the following word puzzle with the help of clues given below.
Down
1. Providing water to the crops.
2. Keeping crop grains for a long time under proper conditions.
5. Certain plants of the same kind grown on a large scale.
Across
3. A machine used for cutting the matured crop.
4. A rabi crop that is also one of the pulses.
6. A process of separating the grain from chaff.
Answer
The solution of word puzzle is given below:
Down
1. IRRIGATION
2. STORAGE
5. CROP
Across
3. HARVESTER
4. GRAM
6. WINNOWING
