NCERT Solutions Class 8 Science Chapter 1 – Crop Production and Management
NCERT Solutions for Class 8 Science Chapter 1: Crop Production and Management
This chapter introduces agricultural practices, types of crops, and modern farming techniques. Understanding these concepts helps students appreciate food production and agricultural science.
Exercise Questions and Answers
Q1. 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) crop
- (b) preparation
- (c) float
- (d) water and nutrients
Q2. Match items in Column A with those in Column B:
| Column A | Column B |
|---|---|
| (i) Kharif crops | (c) Paddy and maize |
| (ii) Rabi crops | (d) Wheat, gram, pea |
| (iii) Chemical fertilizers | (a) Urea and superphosphate |
| (iv) Organic manure | (b) Animal excreta, cow dung |
Q3. Give two examples of each: (a) Kharif crop (b) Rabi crop
Answer:
- (a) Kharif crops: Paddy (rice), Maize, Soybean, Groundnut, Cotton
- (b) Rabi crops: Wheat, Gram (chana), Peas, Mustard, Linseed
Q4. 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: Soil preparation is the first step in farming. It involves loosening and turning the soil using tools like plough, hoe, or cultivator. This process is called tilling or ploughing. Loose soil allows roots to penetrate deeper, improves air circulation, and helps in mixing nutrients. It also brings nutrient-rich soil to the top and buries weeds.
(b) Sowing: Sowing is the process of putting seeds in the soil. Good quality seeds are selected by soaking them in water – damaged seeds float while healthy seeds sink. Seeds are sown at proper depth and distance using traditional tools (funnel-shaped tool) or modern seed drills. Proper spacing ensures adequate sunlight, nutrients, and water for each plant.
(c) Weeding: Weeding is the removal of unwanted plants (weeds) that grow along with crops. Weeds compete with crops for water, nutrients, sunlight, and space. They can be removed manually by hand or using a khurpi, or by using weedicides (chemicals that kill weeds). Weeding should be done before weeds produce flowers and seeds.
(d) Threshing: Threshing is the process of separating grain seeds from the harvested crop (chaff). It can be done manually by beating the dried crop or using machines called threshers. For small quantities, winnowing (using wind to separate lighter chaff from heavier grains) is used.
Q5. Explain how fertilizers are different from manure.
| Fertilizers | Manure |
|---|---|
| Chemical substances | Natural organic substances |
| Prepared in factories | Prepared in fields from decomposition |
| Rich in specific nutrients (N, P, K) | Contains all nutrients but in smaller amounts |
| Does not add humus to soil | Adds humus to soil |
| Expensive | Less expensive/free |
| Examples: Urea, NPK | Examples: Compost, vermicompost |
Key Takeaways
- Crops are plants of the same kind grown on a large scale
- Kharif crops (monsoon) vs Rabi crops (winter) have different growing seasons
- Agricultural practices: soil preparation → sowing → irrigation → weeding → harvesting → storage
- Manure is organic and improves soil structure; fertilizers provide specific nutrients
- Proper storage protects grains from pests and moisture
Key Concepts: Crop Production and Management
This chapter introduces students to agricultural practices in India — from soil preparation to storage. Understanding these practices is important for CBSE Class 8 Science exams and general awareness.
Types of Crops
Crops in India are broadly classified based on the season in which they grow:
- Kharif Crops (Monsoon Crops): Sown in June–July with the monsoon, harvested in September–October. Examples: Paddy (rice), maize, jowar, bajra, cotton, groundnut, soybean.
- Rabi Crops (Winter Crops): Sown in October–November, harvested in March–April. Examples: Wheat, gram, peas, mustard, linseed.
- Zaid Crops: Grown between March and June in summer. Examples: Watermelon, cucumber, muskmelon, bitter gourd.
Agricultural Practices — Step by Step
- 1. Soil Preparation (Tilling/Ploughing): Loosening and turning the soil to allow roots to penetrate, improve aeration, and bring nutrients to the surface. Tools: traditional plough, hoe, cultivator.
- 2. Sowing: Placing seeds in the soil at proper depth and spacing. Seed drill ensures uniform distribution. Good seeds are those that sink in water (denser, higher germination rate).
- 3. Adding Manure and Fertilisers: Plants need nutrients (NPK — Nitrogen, Phosphorus, Potassium). Manure (organic, from plant/animal waste) enriches soil slowly but improves soil texture. Chemical fertilisers provide instant nutrients but may degrade soil over time.
- 4. Irrigation: Supplying water to crops at regular intervals. Methods include moat (pulley), chain pump, dhekli, sprinkler, and drip irrigation. Drip irrigation is the most water-efficient method.
- 5. Weeding: Removing unwanted plants (weeds) that compete with crops for nutrients, water, and space. Methods: manual removal (uprooting), tilling, use of weedicides (herbicides) like 2,4-D.
- 6. Harvesting: Cutting and gathering the mature crop. Traditional method: sickle. Modern method: combine harvester (cuts, threshes, and separates grain in one pass).
- 7. Storage: Storing harvested grains to prevent damage by moisture, pests, and microorganisms. Methods: Jute bags, metallic bins, silos, cold storage. Grain must be dry before storage to prevent fungal growth.
Differences: Manure vs Fertiliser
- Manure: Organic, slow-acting, improves soil structure, eco-friendly, cheaper. Examples: compost, vermicompost, green manure, FYM (Farmyard Manure).
- Fertiliser: Chemical, fast-acting, provides specific nutrients (NPK), does not improve soil texture, overuse causes soil degradation and water pollution. Examples: Urea, DAP, ammonium sulphate.
Animal Husbandry
The rearing of animals for milk, eggs, meat, wool, and work is called animal husbandry. It is closely linked to agriculture in India. Bees (apiculture), fish (pisciculture/aquaculture), and poultry (poultry farming) are important components.
Important Board Exam Questions
- What is the difference between Kharif and Rabi crops? Give two examples each.
- What is a seed drill? What is its advantage over traditional sowing?
- Distinguish between manure and fertiliser.
- What is irrigation? Describe any two methods of irrigation.
- Why is weeding necessary? Name one chemical used as a weedicide.
- What is a combine harvester? What does it do?
- Why must grains be dried before storage?
FAQs
Q: What is vermicompost?
A: Vermicompost is compost prepared using earthworms. Earthworms break down organic waste into nutrient-rich manure. It is an excellent organic fertiliser.
Q: Why is drip irrigation recommended for dry regions?
A: In drip irrigation, water is delivered directly to the root zone of plants through small pipes and drippers. Water loss due to evaporation and runoff is minimised, making it highly efficient for water-scarce areas.
Q: What is crop rotation?
A: Crop rotation is the practice of growing different types of crops in the same field in sequential seasons. It improves soil fertility (legumes fix nitrogen), controls pests and diseases, and reduces dependence on chemical fertilisers.
