Environmental Studies · Biology

Soil Science and Fertilizers

1,537 Questions

Soil science focuses on soil formation, classification, and fertility management using fertilizers and organic amendments. Agricultural and environmental science exams heavily feature questions on biofertilizers, mycorrhiza, and phytoremediation. Practice these questions to build a strong understanding of soil nutrient cycles.

Phytoremediation techniquesOrganic soil amendmentsBiofertilizers and mycorrhizaNitrous oxide emissionsIn-situ soil remediationGreen manuring effects

Soil Science and Fertilizers Questions

Multiple choice

What is the disadvantage of the sandy soil?

  1. It cannot hold much water

  2. It provides air to the growing plant species.

  3. It can be plunged very easily.

  4. Its fertility can be increased.

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Sandy soil has large particles with high permeability and large pore spaces, causing water to drain rapidly through it. This poor water and nutrient retention capacity is its primary disadvantage for agricultural use, as plants cannot access water when they need it.

Multiple choice

Manures are natural fertilisers. Which of the following is an advantage of manures?

  1. They are bulky with low nutrient content.

  2. They contain nitrogen, phosphorus and potassium.

  3. Manures add organic matter to the soil.

  4. The nutrients get released slowly in manures.

  5. Manures are not nutrient-specific.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is the correct option as this is an advantage of manures. They add organic matter to the soil called humus.

Multiple choice

Which of the following factors does not contribute in the improvement of quality of soil?

  1. Manures

  2. Soil organisms

  3. Afforestation

  4. Overgrazing

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Manures add organic matter and nutrients, soil organisms enhance decomposition and nutrient cycling, and afforestation prevents erosion and improves soil structure. Overgrazing degrades soil by removing protective vegetation, compacting the land, and increasing erosion - it harms rather than helps soil quality.

Multiple choice

Select the incorrect statement:

  1. Humans can impact soil formation by removing vegetation.

  2. Microorganisms help in increasing the soil fertility

  3. Vegetation cannot prevent soil erosion

  4. Growth of plants is affected by the density and pH of the soil
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Statement C is incorrect because vegetation plays a crucial role in preventing soil erosion through several mechanisms: plant roots hold soil particles together, canopy cover reduces raindrop impact, and vegetation slows water runoff. Statements A, B, and D are all scientifically accurate about human impacts, microorganism benefits, and soil-plant relationships.

Multiple choice

What should be added to soil if it is alkaline in nature?

  1. Lime

  2. Calcium Carbonate

  3. Peat

  4. Water
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

To correct alkaline soil (high pH), acidic amendments are needed. Peat (C) is acidic and helps neutralize alkalinity. Lime (A) and calcium carbonate (B) would increase alkalinity further, making the problem worse. Water (D) doesn't change pH. The principle is to apply the opposite type of amendment to move pH toward neutral.

Multiple choice

The side effect(s) of heavy and constant grazing is/are that the

  1. upper layers of soil are loosened and are eroded

  2. lower layers are made more compact and root respiration is interfered with

  3. lower compact layers make root penetration difficult

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Heavy grazing affects soil at multiple levels: it loosens and exposes upper soil layers to erosion (option A), compacts lower layers making them impermeable and hard for roots (option B), and these compacted layers prevent proper root penetration (option C). Since all three effects occur simultaneously due to heavy grazing, option D 'All of the above' is the correct answer.

Multiple choice

Which one of the following best represents pH?

  1. Phosphorus and hydrogen content in soil

  2. Percentage of Hydrogen in soil

  3. Proportion of potash and hydrogen in soil

  4. Concentration of hydrogen ions in the soil
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

pH measures the concentration of hydrogen ions (H+) in a solution, including soil. A lower pH indicates higher acidity (more H+ ions), while higher pH means more alkaline (fewer H+ ions). Options A, B, and C are incorrect because pH is not about phosphorus, percentage of hydrogen, or potash content.