Exercises
A. Choose the correct option.
1. Which of these is not a rabi crop?
a Rice b. Barley c. Wheat d. Peas and beans
Answer. a. Rice (Rabi crops are winter crops like wheat, barley, peas; rice is kharif).
2 Which of these is a natural fertilizer?
a. Compost b. Manure c. Bone meal d. All of these
Answer. d. All of these (Compost, manure, and bone meal are natural fertilizers).
3. Which of these methods of irrigation leads to a lot of water wastage?
a. Dhekli and rahat b. Drip irrigation c. Sprinkler irrigation d. All of these
Answer. a. Dhekli and rahat(Traditional methods waste water; drip/sprinkler are efficient).
4. Which of these helps us to get rid of pests?
a. Pesticides b. Weedicides c. Thresher d. compost
Answer. a. Pesticides (Chemicals that kill pests; weedicides target weeds).
5. Which of these help in naturally fixing nitrogen of the air?
a. Lightning b. Nitrogen-fixing bacteria c. Decomposition of dead remains of plants and animals d. All of these
Answer. d. All of these (Lightning, bacteria, and decomposition fix nitrogen).
B. Fill in the blanks with the correct words.
1. Agriculture involves growing. __________ (plants/animals) and rearing._______________
for food and other useful products.
Answer. plants, animals
2. _________ (Rice/Wheat) is a kharif crop.
Answer. Rice
3. Manure and compost are ___________(natural/chemical) fertilizers.
Answer.Natural
4. A __________ (plough/seed drill) is used to prepare soil by turning it.
Answer. Plough
5. _____________ (Sprinkling seeds manually/Using a seed drill) ensures sowing of seeds at a proper distance and depth.
Answer. Using a seed drill
6. Big lumps of soil are broken by using a _______ (seed drill/seed leveller).
Answer. leveller
7. ____________ (Dhekli Drip irrigation is a modern method of irrigation.
Answer. Drip irrigation
8. When excess water gets collected on the field, it causes a condition called._________
(waterlogging/weeding).
Answer. waterlogging
9. Grains get separated from husk by the process of _________ (harvesting/threshing).
Answer. threshing
10. A special bacteria that helps in fixing nitrogen of the air is found in the ________
(stems/roots) of _________ (all/leguminous) plants.
Answer. roots, leguminous
C. Answer the following questions.
1. What do we mean by agriculture?
Answer. Agriculture is the practice of cultivating crops (like wheat, rice) and rearing livestock (cows, poultry) for food, fiber, and other products.
2. Differentiate between rabi and kharif crops. Give two examples of each.
- Answer. Season of Cultivation:
- Rabi: Grown in winter (October–March).
- Kharif: Grown in monsoon (June–September).
- Climate Requirement:
- Rabi: Needs cool weather during growth and warmth during ripening.
- Kharif: Requires warm weather and heavy rainfall.
- Harvesting Time:
- Rabi: Harvested in spring (March–April).
- Kharif: Harvested in autumn (September–October).
- Examples:
- Rabi: Wheat, Peas.
- Kharif: Rice, Cotton.
3. List in the correct order the steps followed for growing crops on an agricultural field.
Answer 1. Soil preparation (ploughing, levelling).
2. Sowing seeds.
3. Adding manure/fertilizers.
4. Irrigation.
5. Weeding/pest control.
6. Harvesting.
7. Storage.
4. Discuss how soil is prepared for agriculture
Answer. Soil preparation involves ploughing, levelling, and adding manure to loosen soil, improve aeration, and enrich nutrients for optimal crop growth.
5. How do earthworms help farmers?
Answer. Earthworms improve soil aeration, enhance nutrient recycling, and boost fertility by decomposing organic matter into nutrient-rich vermicompost.
6. Why do we need to use fertilizers in growing crops?
Answer. Fertilizers replenish essential soil nutrients (like nitrogen, phosphorus, and potassium) depleted by repeated farming, ensuring healthy plant growth and higher crop yields to meet food demands.
7. Differentiate between natural and chemical fertilizers.
Answer. Natural Fertilizers
- Source: Organic matter (e.g., compost, manure, bone meal).
- Nutrient Release: Slow and gradual.
- Soil Health: Improves soil structure and water retention.
- Eco-Impact: Environmentally friendly, no pollution.
- Cost: Low or free (made from waste).
Chemical Fertilizers
- Source: Synthetic (e.g., urea, NPK).
- Nutrient Release: Fast and immediate.
- Soil Health: May degrade soil quality over time.
- Eco-Impact: Can cause water pollution (eutrophication).
- Cost: Expensive due to manufacturing.
8. What is a seed drill?
Answer. A seed drill is a farming tool that sows seeds uniformly at the correct depth and spacing, ensuring efficient germination, reducing waste, and saving time compared to manual sowing
9. What do we mean by irrigation? How does it help in agriculture?
Answer. Irrigation is the artificial supply of water to crops. It ensures consistent growth, prevents drought stress, and boosts yields by providing moisture in rain-deficient areas.
10. Name any three traditional and two modern methods of irrigation.
Answer. Traditional and modern method of Irrigation are mentioned below:
Traditional Methods:
- Dhekli (Lever-based lifting).
- Rahat (Persian wheel).
- Moat (Pulley system).
Modern Methods:
- Drip irrigation (Water-saving).
- Sprinklers (Rain-like spray).
11. What are pests? Name any three pests.
Answer. Pests are harmful organisms (insects, rodents, etc.) that damage crops, reducing yield and quality. Examples:
- Locusts (devour leaves).
- Aphids (suck plant sap).
- Rats (destroy stored grains)
12. Discuss two methods that farmers use for getting a high yield of crops.
Answer 1. Crop Rotation: Alternating crops (e.g., wheat and legumes) replenishes soil nutrients naturally, preventing depletion and boosting yield.
2. Mixed cultivation: is growing two or more crops together on the same land to improve soil fertility, reduce pests, and maximize yield efficiently.
13. How do leguminous plants help in fixing nitrogen if the air?
Answer. Leguminous plants (e.g., peas, beans) host Rhizobium bacteria in root nodules, which convert atmospheric nitrogen into soluble nitrates, enriching soil fertility naturally