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

The process of sowing is putting ________ in the soil.

  1. root

  2. seed

  3. chemical

  4. DDT
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Sowing is the agricultural practice of placing seeds into the soil at the appropriate depth for germination and growth. Roots develop from seeds, chemicals and DDT are not sown, and sowing specifically targets seeds not other plant parts.

Multiple choice

Which of the following fertilizers has the highest percentage of nitrogen?

  1. Calcium ammonium nitrate

  2. Ammonium sulphate

  3. Calcium nitrate

  4. Urea
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Urea (CO(NH2)2) contains approximately 46% nitrogen by mass, the highest among common nitrogen fertilizers. Calcium ammonium nitrate has ~27%, ammonium sulphate has ~21%, and calcium nitrate has ~15% nitrogen. Urea's high N content makes it efficient.

Multiple choice

Which of the following fertilizers has the highest percentage of nitrogen?

  1. Calcium ammonium nitrate

  2. Ammonium sulphate

  3. Calcium nitrate

  4. Urea
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Urea (CO(NH2)2) contains approximately 46% nitrogen by mass, which is the highest among all common nitrogen fertilizers. Calcium ammonium nitrate contains about 27-28% nitrogen, ammonium sulphate contains 21%, and calcium nitrate contains about 15-17%. The high nitrogen content makes urea an efficient and economical choice for farmers.

Multiple choice

Which of the following can be the reasons of soil acidification?

  1. Heavy rainfall
  2. Use of fertilizer
  3. Shifting cultivation

  1. 1 and 2 only

  2. 1 and 3 only

  3. 2 and 3 only

  4. 1, 2 and 3
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Increase of concentration of hydrogen ions in the soil is known as soil acidification. The main cause of soil acidification is inefficient use of nitrogen fertilizer. Heavy rainfall may also lead to soil acidification as the bases in soils are washed away. Shifting cultivation does not lead to soil acidification, although it leads to generating infertile soil. 

Multiple choice

In ecology, the term “standing crop” signifies

  1. total biomass of whole organic matter

  2. total biomass of heterotrophs

  3. total area covered by crops

  4. total increase in crop production by use of fertilizers
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In ecology, the term “standing crop” signifies the total biomass of whole organic matter of an ecosystem.

Multiple choice

Leguminous plants help in the replenishment of the soil with

  1. oxygen

  2. nitrogen

  3. hydrogen

  4. carbon dioxide

  5. helium
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Rhizobium is present in the root nodules of leguminous plants. These bacteria convert atmospheric nitrogen into simpler nitrogen compounds that can be easily absorbed by plants. Hence, it is the correct answer.

Multiple choice

Which of the following statements is incorrect?

  1. Loose soil particles have more air spaces

  2. Loose soil particles hold less water for longer duration

  3. Loose soil helps roots to penetrate deep through the layers of soil

  4. Loose soil promotes the growth of useful soil microbes

  5. While turning the soil during ploughing, nutrient-rich soil is brought up from lower level of soil
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Correct Answer: Loose soil particles hold less water for longer duration