Fertilizers MCQs Quiz | Class 9

This Class IX Science (Code 086) quiz focuses on Unit IV: Food Production, specifically covering the topic of Fertilizers. Questions test your understanding of their use, purpose, basic advantages, and limitations compared to manure. Submit your answers to check your score and download the PDF answer key.

Overview of Fertilizers

Fertilizers are commercially produced plant nutrients. They supply nitrogen, phosphorus, and potassium (NPK) to ensure good vegetative growth (leaves, branches, and flowers), giving rise to healthy plants. Unlike manure, which is organic and bulky, fertilizers are inorganic chemicals or concentrated organic compounds manufactured in factories.

Purpose and Nutrients

The primary purpose of fertilizers is to provide specific nutrients that might be lacking in the soil. The three critical macronutrients supplied are:

  • Nitrogen (N): Essential for leaf growth and green color.
  • Phosphorus (P): Important for root development and flowering.
  • Potassium (K): vital for overall plant health and disease resistance.

Advantages of Fertilizers

Farmers use fertilizers because they yield quick results and have several benefits:

  • They are nutrient-specific, allowing farmers to target a specific deficiency (e.g., adding only Nitrogen).
  • They are concentrated, making them easy to transport, store, and apply in smaller quantities.
  • Being soluble in water, they are readily absorbed by plant roots.
  • They significantly increase crop yield in the short term.

Limitations and Disadvantages

Despite their benefits, excessive or continuous use of fertilizers poses serious environmental threats:

  • Soil Degradation: Continuous use can alter soil chemistry (making it too acidic or alkaline) and destroy soil texture.
  • Loss of Microbes: They may harm beneficial soil microorganisms and earthworms that help recycle nutrients naturally.
  • No Humus: Fertilizers do not add organic matter (humus) to the soil, reducing its water-holding capacity over time.
  • Water Pollution: Excess fertilizers wash away into water bodies (runoff), causing eutrophication—an overgrowth of algae that depletes oxygen in water, killing aquatic life.

Comparison: Manure vs. Fertilizers

Feature Manure Fertilizer
Source Natural decomposition of animal/plant waste Chemically manufactured in factories
Nutrients Small amounts of all nutrients Rich in specific nutrients (N, P, K)
Humus Adds a lot of humus to soil Does not add any humus
Absorption Slowly absorbed by plants Rapidly absorbed (water soluble)

Extra Practice Questions

  1. Why are fertilizers considered nutrient-specific?
  2. Name one common nitrogenous fertilizer.
  3. How does fertilizer runoff affect lakes and ponds?
  4. Why should fertilizers be applied carefully in terms of dosage?
  5. What happens to the soil texture if only fertilizers are used for years?