Crop Production and Management – Case-based Questions with Answers
Class 8
Science
Chapter 1
Crop Production and Management — 20 Case-Based Questions (Topic-wise)
CBSE Class 8 Science – Chapter Wise Study Materials Based on NCERT
CBSE Board Examinations — Chapter Presentation (Systematic):
- Unit Focus: Apply concepts of crop production, soil management, irrigation, pest control and post-harvest practices to real-life scenarios.
- Question Style: Case-based — read the scenario carefully, answer short direct questions that test understanding and application.
- Exam Tip: For case questions, identify keywords, list relevant steps or reasons, and provide one example when asked.
These Case-Based Questions with Answers are designed strictly as per the NCERT syllabus, making them ideal for CBSE Class 8 board exams standard.
Topic A: Basics & Cropping Seasons (Cases 1–5)
Case 1: Riya's village receives heavy monsoon this year. Her neighbour plans to sow paddy, while another friend wants to sow wheat.
Q1a: Which of these crops is suitable for the monsoon season and why?
A1a: Paddy is suitable for the monsoon (kharif) season because it requires abundant water and is sown with the onset of monsoon.
Q1b: When should wheat be sown and why is it not ideal now?
A1b: Wheat is a rabi crop sown in winter (Oct–Nov); sowing it during monsoon is unsuitable as it requires cooler weather for germination.
Case 2: A farmer has limited land and wants to grow two crops together to reduce risk.
Q2: Suggest a suitable mixed cropping pair and one advantage.
A2: Maize + beans is a good pair; advantage: legumes (beans) fix nitrogen, benefiting maize and increasing overall yield and nutrition.
Case 3: The school gardener wants a crop that provides quick returns and another for regular food supply.
Q3: Name one cash crop and one staple crop suitable for this purpose.
A3: Cash crop: tomato or vegetable for market sale. Staple crop: wheat or rice for regular food supply.
Case 4: A plot is used for kharif crops this year; the farmer plans another crop after harvest using residual moisture.
Q4: Which practice does this describe and what is its benefit?
A4: This describes multiple cropping — growing more than one crop in a year. Benefit: better land use and increased total productivity.
Case 5: A student asks why certain crops are grouped as kharif or rabi.
Q5: Explain the primary basis for this grouping.
A5: Grouping depends on climatic requirements — kharif crops need monsoon rainfall and warm weather; rabi crops require cooler temperatures during sowing and less water.
Topic B: Soil, Manure & Fertilizers (Cases 6–10)
Case 6: A farmer notices that his field has become hard and yields are declining.
Q6a: Suggest two probable causes related to soil and one corrective measure.
A6a: Causes: loss of organic matter and compaction. Corrective measure: add organic manure/compost and practice ploughing to improve soil aeration and structure.
Case 7: A group of students prepare compost using kitchen waste but wonder about differences with chemical fertilizers.
Q7: List two differences between organic compost and chemical fertilizers.
A7: Compost improves soil structure and releases nutrients slowly; chemical fertilizers supply specific nutrients quickly but do not improve soil texture and may cause pollution if overused.
Case 8: Soil test shows low phosphorus in a field.
Q8: Which type of fertilizer should the farmer apply and why?
A8: Apply phosphate fertilizers (e.g., single superphosphate) because they supply phosphorus needed for root growth and flowering.
Case 9: Heavy rains have washed off topsoil from a slope near the school farm.
Q9: Suggest a soil conservation method suitable on slopes.
A9: Terracing or planting cover crops — both reduce runoff and prevent erosion of topsoil on slopes.
Case 10: A farmer wants to prepare a small vermicompost pit at home.
Q10: Briefly outline steps to make vermicompost.
A10: Collect kitchen/plant waste, mix with cow dung or soil, place in a shaded bin, add earthworms (e.g., Eisenia), keep moist and aerated; after weeks the material becomes nutrient-rich vermicompost.
Topic C: Irrigation & Water Management (Cases 11–14)
Case 11: A farmer in a semi-arid area must choose an irrigation method to conserve water.
Q11: Which irrigation method is most water-efficient and why?
A11: Drip irrigation is most efficient as it delivers water directly to the root zone, minimising evaporation and runoff.
Case 12: After installing a sprinkler system, a field shows patchy growth due to wind drift.
Q12: What modification or precaution can reduce this problem?
A12: Use low-angle sprinklers, schedule irrigation during low-wind periods, or use windbreaks to reduce drift and ensure more uniform water distribution.
Case 13: Excessive irrigation has caused standing water in parts of a field.
Q13: Name two problems that can result and one remedy.
A13: Problems: waterlogging and increased risk of root rot; Remedy: improve drainage or reduce irrigation frequency and adopt raised beds.
Case 14: A village plans rainwater harvesting to help irrigation during dry spells.
Q14: Give one simple method to harvest rainwater for farms.
A14: Build farm ponds or check dams to collect runoff and store rainwater for supplemental irrigation during dry periods.
Topic D: Pest Management, Harvesting & Storage (Cases 15–20)
Case 15: A farmer finds caterpillar damage on maize leaves shortly before harvest.
Q15a: Suggest one immediate biological and one chemical control measure.
A15a: Biological: release Trichogramma or encourage birds/beneficial insects; Chemical: a recommended selective insecticide applied as per guidelines, taking care to follow safety precautions.
Case 16: Stored grains in a household are infested by weevils.
Q16: Suggest two safe storage practices to prevent such infestation.
A16: Properly dry grains before storage and keep them in airtight containers; periodic cleaning of storage areas and using natural repellents like neem leaves can help.
Case 17: A school farm uses minimal pesticides and wants to adopt IPM.
Q17: List three components of IPM the school can implement.
A17: Components: biological controls (beneficial insects), cultural practices (crop rotation, timely sowing), and monitoring with pheromone/trap methods; chemical pesticides only as last resort.
Case 18: The harvest is approaching and the farmer must choose between manual and mechanised harvesting.
Q18: Mention two advantages and one limitation of mechanised harvesting.
A18: Advantages: faster harvesting, reduced labour and lower post-harvest losses. Limitation: high initial cost and need for skilled operators.
Case 19: A farmer observes that overuse of nitrogenous fertilizer has led to lush vegetative growth but low fruiting.
Q19: Explain why this might happen and one corrective practice.
A19: Excess nitrogen promotes leafy growth at the expense of flowering/fruiting. Corrective practice: balanced fertilisation based on soil testing, reducing nitrogen and ensuring adequate phosphorus and potassium.
Case 20: After harvesting, the farmer wants to minimise post-harvest losses and fetch better prices.
Q20: Suggest three post-harvest practices he should follow.
A20: (1) Dry produce properly to safe moisture level, (2) Clean and sort grains to remove impurities, (3) Store in dry, ventilated or airtight containers and monitor for pests.
Note: All Case-Based Questions and Answers are topic-wise and strictly follow the NCERT syllabus, making them ideal for CBSE Class 8 board exams standard.
Tip: For exam answers, keep case responses concise — identify the concept, list 2–3 points, and give a short example when required.