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

_______ is used for the reclamation of acidic soil.

  1. Lime

  2. Rice

  3. Sodium

  4. Calcium
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Lime (calcium carbonate or calcium oxide) neutralizes soil acidity by raising pH levels, making nutrients more available to plants. Calcium is an element, while lime is the specific agricultural amendment applied to acidic soils.

Multiple choice

Why is organic manure better than fertilisers?

  1. Decreases the number of microbes

  2. Easily absorbed

  3. Improves the texture of the soil

  4. Easily washed away by water

  5. Decreases the water holding capacity of the soil
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Manures add plenty of humus to the soil and improves the texture of the soil.

Multiple choice

Which method is used by the farmers to enrich the soil with nutrients?

  1. Rhizobium enhancement

  2. Harvesting crops

  3. Manure addition

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

Rhizobium enhancement, harvesting crops and spraying insecticide have nothing to do with the enrichment of the soil with nutrients. Manure is the organic substance, rich in humus and helps increasing the soil fertility.

Multiple choice

Recent trends in agricultural productivity have shown a decline in marginal productivity of soil in relation to the application of fertilizers. What is the most important reason behind this?

  1. Less than optimal application of chemical fertilizers by farmers in India

  2. Skewed application of fertilizers with bias in favour of nitrogenous fertilizers

  3. Declining domestic production of straight fertilizers like Urea and DAP

  4. Inadequate credit facilities to the farmer for buying high quality farm inputs
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Three of the most important types of fertilizers in India are Nitrogen, Phosphorus and Potassium (NPK). For India, the standard ratio of application of NPK fertilizers has been estimated to be 4 : 2 : 1, but the fertilizer application is generally seen to be biased in favour of nitrogenous fertilizers. The bias reached its peak in 1996-1997 when the ratio was 10 : 3 : 1. According to latest recorded figures, the ratio of application of NPK fertilizers is 5.5 : 2 : 1.

Multiple choice

Adil planted a plant in a pot of soil with water and fertilizer. He then covered that plant with a big black trash bag. The plant will eventually die due to lack of_____.

  1. fertlilizer

  2. water

  3. sunlight

  4. soil

  5. cannot be determined
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is a right answer. As the plant is covered with a big black trash bag, because of which the plant is not able to absorb sunlight, and eventually will not be able to make its food and will die after some time.

Multiple choice

While sowing seeds, the fertiliser commonly used contains

  1. nitrates

  2. potash

  3. phosphorous

  4. calcium
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Nitrogen-containing fertilizers like ammonium nitrate and calcium ammonium nitrate are commonly applied during sowing to support early vegetative growth. While phosphorus (DAP) is also used at sowing, nitrogen fertilizers containing nitrates are very common. Potash is usually applied later, and calcium is a secondary nutrient.

Multiple choice

Which of the following statements is incorrect about manure?

  1. Manure is prepared in fields.

  2. Manure is prepared in factories.

  3. Manure is obtained by decomposition of dung, animal wastes, etc.

  4. Manure provides humus to the soil.

  5. Manure is relatively less rich in plant nutrients as compared to fertilisers.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Manure is not prepared in factories. Fertilisers are prepared in factories.

Multiple choice

Roughage does not provide nutrients, still it is essential. Why?

  1. It can be used as a feed for beef cattle in the form of cotton grain trash.

  2. It helps in getting rid of undigested food.

  3. It keeps the skin healthy.

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

Roughage (dietary fibers) is provided by all plant products like fruits, pulses, vegetables, etc. It acts as food for animals, helps us in getting rid of the undigested food from the body and keeps our skin healthy.

Multiple choice

Why is the preparation of soil an important task in agriculture?

  1. It kills microbes present in soil.

  2. It brings nutrient-rich soil to the top.

  3. It removes weeds present along with crop.

  4. It kills earthworms present in soil.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Soil preparation (tilling) brings nutrient-rich subsoil to the surface where crops can access these nutrients. It improves aeration and root penetration. Tilling does not primarily aim to kill microbes or earthworms (both beneficial), nor does it directly remove weeds (that's weeding).