Crop Production and Management — Question 9
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What are weeds? How can we control them?
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.
Chapter Overview: Crop Production and Management
This chapter covers the complete agricultural cycle from soil preparation to grain storage. Students learn about Kharif and Rabi crops, modern and traditional irrigation methods, the difference between manure and fertiliser, and how food grains are harvested, threshed, and stored. Animal husbandry is introduced as a complementary food production practice.
Board Exam Weightage: 5-7 marks | Difficulty: Moderate
Key Formulas & Concepts
| Concept | Details |
|---|---|
| Kharif Crops | Sown in June-July (monsoon season); harvested in September-October. Examples: paddy, maize, soybean, cotton |
| Rabi Crops | Sown in October-November (winter); harvested in March-April. Examples: wheat, gram, pea, mustard |
| Drip Irrigation | Water delivered drop by drop at plant roots; most water-efficient method |
| Sprinkler Irrigation | Water sprayed through rotating nozzles; suitable for uneven land |
Must-Know Concepts
- Soil preparation loosens soil and brings nutrients to the surface
- Seed drill ensures uniform spacing and depth of sowing
- Manure is organic (plant/animal waste), fertiliser is chemical (NPK)
- Weeds compete with crops for water, nutrients, and sunlight
- Combine harvester does harvesting and threshing simultaneously
- Grains must be dried to reduce moisture before storage
Manure vs Fertiliser
| Feature | Manure | Fertiliser |
|---|---|---|
| Source | Plant/animal waste (organic) | Chemical factories (inorganic) |
| Nutrients | All nutrients + humus | Specific (N, P, or K) |
| Soil Effect | Improves soil texture and water-holding | No improvement; may degrade soil over time |
| Speed | Slow-acting, long-lasting | Fast-acting, short-term |
| Pollution | None | Excessive use causes soil/water pollution |
Common Mistakes to Avoid
- Confusing Kharif and Rabi crops and their growing seasons
- Thinking manure and fertiliser are interchangeable
- Not knowing the difference between threshing and winnowing
- Forgetting that irrigation means artificial water supply, not rainfall
Scoring Tips
- Learn crop classification with seasonal memory aids
- Draw flowcharts of the complete crop production process
- Compare irrigation methods in a table for quick revision
- Practice NCERT in-text questions for definitions
Frequently Asked Questions
Q: How many marks does this chapter carry in the exam?
A: Approximately 5-7 marks in the annual exam.
Q: What question types are commonly asked?
A: MCQs (1 mark), Very Short Answer (2 marks), Short Answer (3 marks), and Long Answer / Diagram (5 marks).
Q: Is this chapter important for competitive exams?
A: Yes, concepts from this chapter appear in NTSE, Olympiad, and other science competitions.