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 biology improvement in food resources manure manures and fertilisers role of organic manures in soil management

A few gram seeds were placed in each of the three pots A, B and C containing soil. The soil in Pot A is mixed some green twigs and leaves. The soil in pot B is mixed with old cow dung while soil of pot C is mixed with urea. Pots are watered regularly. Which of the following will be observed after 10 days?

  1. Lot of growth in A

  2. Not much growth in B

  3. Lot of growth in B but very little growth in C

  4. Very little growth in A but lot of growth in B and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Manure is an organic substance produced by the decomposition of plant and animal wastes in the presence of microorganism and used as fertilizers. Thus, the fresh manure contains decomposing bacteria along with active digestive enzymes. These enzymes contribute to the faster heating of the manure which accelerates the decomposition of organic materials by the soil microorganisms. The end result of better decomposition of organic material is faster nutrient release to the plant. When urea is placed on the surface of the soil, a chemical reaction takes place that changes the urea to ammonium bicarbonate. Urea should be mixed in with the soil for maximum effectiveness. For plants that love acidic soils, urea is one of the top fertilizers for acidifying soils. Hence, seeds will grow most in pots B and C.

Multiple choice biology improvement in food resources manure manures and fertilisers role of organic manures in soil management

Fairly good yield of rice can be had over a number of years without adding any nitrogenous manures because

  1. They require very minute quantities of nitrogen.

  2. Their roots have nitrogen-fixing bacterial associated with them.

  3. There are nitrogen-fixing algae in the rice fields.

  4. Rice plant do not require any nitrogen.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The rice paddy field contains the Azolla weeds with the nitrogen-fixing cyanobacteria which can help in the conversion of the atmospheric nitrogen to nitrates. This nitrate can be used for the growth of the plants without the introduction of nitrogenous manures externally. These organisms help increase the yield of the rice plants. 

Thus, the correct answer is option C. 

Multiple choice biology improvement in food resources manure manures and fertilisers role of organic manures in soil management

Different types manures are

  1. Farmyard, compost and green

  2. Green and farmyard

  3. Green and compost

  4. Farmyard and compost
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Manure is an organic substance produced by the decomposition of plant and animal wastes in the presence of microorganism and used as fertilizers. Farmyard manure, compost and green manure are the most important and widely used bulky organic manures. Farmyard manure is the decomposed mixture of excreta of farm animals along with litter and leftover material from fodder fed to the cattle. Green manure and compost are the decomposed substance of crop. It is helpful in maintaining soil form, aeration and hydration. 

Multiple choice biology improvement in food resources manure manures and fertilisers role of organic manures in soil management

Fertilizers can cause _________________

  1. Burn in plants

  2. Burn in microorganism

  3. Burn in soil

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

  • Fertilizer can cause burn in the plants when too much fertilizer is applied. It is a chemical compound that can dry out the leaves and damage or even cause the death of the plant. 
  • Fertilizers vary in their tendency to burn roughly in accordance with their salt index. 

Therefore, the correct answer is option A.

Multiple choice biology improvement in food resources manure manures and fertilisers role of organic manures in soil management

The unpleasant odor of manure can be prevented by____________

  1. Adding water to it

  2. By using it fresh

  3. Both A and B

  4. By injecting it in the soil
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

  • Manure is an organic substance produced by the decomposition of plant and animal wastes in the presence of microorganisms and thus, produces an unpleasant odor. 
  • To prevent such odor they are usually knifed (injected) directly into the soil. Manure from pig and cattle is usually spread on fields using a manure spreader. 

Therefore, the correct answer is option D.

Multiple choice biology improvement in food resources manure manures and fertilisers role of organic manures in soil management

Fertilizers can be classified as__________________

  1. Straight and multinutrient

  2. Inorganic and organic

  3. Synthetic and Inorganic

  4. Both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • Fertilizers, chemically synthesized substances that are rich in plant nutrients such as NPK. They are artificially made but have a rapid response. Overuse of fertilizers can cause negative effects such as decreased soil fertility.
  • Fertilizers are classified according to whether they provide a single nutrient (say, N, P, or K), in which case they are classified as straight fertilizers. Multinutrient fertilizers (or complex fertilizers) provide two or more nutrients e.g., N and P. 
  • Fertilizers are also sometimes classified as inorganic and organic on the basis of molecular structure. Organic fertilizers are derived from plant or animal sources, whereas inorganic fertilizers contain minerals and synthetic chemicals.
  • Therefore, the correct answer is option D.
Multiple choice biology improvement in food resources manure manures and fertilisers role of organic manures in soil management

Find out the correct sentence about manure.
i) Manure contains large quantities of organic matter and small quantities of nutrients.
(ii) It increases the water holding capacity of sandy soil.
(iii) It helps in draining out of the excess of water from the clayey soil.
(iv) Its excessive use pollutes the environment because it is made of animal excretory waste.

  1. (i) and (iii)

  2. (i) and (ii)

  3. (ii) and (iii)

  4. (iii) and (iv)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Bulky organic manure contains large quantities of organic matter and small quantities of nutrients. It increases the water holding capacity of sandy soil. This makes more water available to plants. It prevents the environment pollution, because it recycles the animal excretory waste. Therefore, option B is correct. 

Multiple choice biology natural resources and agriculture manure manures and fertilisers role of organic manures in soil management

When a fertilizer contains at least two or more nutrients is called as _____ fertilizer.

  1. Simple

  2. Complex

  3. Chemical

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Complex fertilizers (also known as compound fertlizers) are made from mixing two or more of macro-nutrient type fertilizers. They may also be further blended with elements that provide some of the less-common plant nutrients (known as secondary or trace nutrients, such as sulfur, calcium and magnesium).

Thus, the correct answer is option B.

Multiple choice biology natural resources and agriculture manure manures and fertilisers role of organic manures in soil management

Which of the following fertilizer contains insoluble citric acid?

  1. Potassium fertilizers

  2. Nitrogen fertilizers

  3. Phosphatic fertilizers

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

There are different forms of phosphatic fertilizers. There are citrate soluble and insoluble forms of phosphoric fertilizers. rock phosphate and bone meal are the common examples of phosphatic fertilizers. These fertilizers contain the insoluble form of citric acid and does not dissolves in the water.

Thus, the correct answer is option C. 

Multiple choice biology natural resources and agriculture manure manures and fertilisers role of organic manures in soil management

Which of the following fertilizer is used for the increased production of coffee, corn and soybeans?

  1. Phosphatic fertilizer

  2. Nitrogenous fertilizer

  3. Potassium fertilizer

  4. Nitrogen and potassium combined fertlizer
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The increase in fertilizer consumption is a fundamental driver for increasing agricultural productivity. so, for increasing the production of coffee, corn and soyabeans nitrogen and potassium combined fertilizer is used. Nitrogen helps plants grow quickly, while also increasing the production of seed and fruit, and bettering the quality of leaf and forage crops and Potassium, assists in photosynthesis, fruit quality, the building of protein, and the reduction of disease.
So, the correct answer is option D.
Multiple choice biology natural resources and agriculture manure manures and fertilisers role of organic manures in soil management

Potassium nitrate fertilizer contains .......... of nitrogen.

  1. 46%

  2. 44%

  3. 21%

  4. 13%
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Potassium nitrate is one of the common fertilizer which is used for the growth of the plants. Potassium nitrate contains about 13% of nitrogen. There is about 44% of potassium in oxide form. The addition of this fertilizer generally results in an increase in the pH. This fertilizer readily supplies nitrogen to the soil which can be taken up by the plants. 

Thus, the correct answer is option D. 

Multiple choice biology natural resources and agriculture manure manures and fertilisers role of organic manures in soil management

50 kg of superphosphate adds .......... of phosphorus to the soil.

  1. 8%

  2. 10%

  3. 13%

  4. 44%
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

There are different forms of fertilizers which are used for supplying phosphorus. Superphosphate is the common synthetic form of fertilizer which is used for enriching the soil with phosphate. About 50 kg of superphosphate adds 8% of phosphorus to the soil. Triple phosphate can also be used for adding phosphate to the soil. 

Thus, the correct answer is option A. 

Multiple choice biology natural resources and agriculture manure manures and fertilisers role of organic manures in soil management

Which of the following is the phosphatic fertilizer?

  1. Urea

  2. NPK

  3. Superphosphate

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Superphosphate is a phosphatic fertilizer. It is most commonly found as single super phosphate, double super phosphate and triple super phosphate. The main component of this fertilizer is phosphate. It's phosphate part get dissolved in the soil water when it is applied in the field. The dissolved phosphorus is easily taken up by the roots of growing plants. Whereas, urea is a nitrogen fertilizer and NPK is made up of nitrogen, phosphorus and potassium. So, the correct option is C. 
Multiple choice biology natural resources and agriculture manure manures and fertilisers role of organic manures in soil management

Which of the following is not of the three plant macronutrients included in most fertilizers?

  1. O

  2. N

  3. P

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

The three primary plant macronutrients are Nitrogen (N), Phosphorus (P), and Potassium (K). Oxygen (O) is obtained by plants from the air and water, not typically added as a fertilizer macronutrient.

Multiple choice chemistry planet earth acid deposition air and air pollution natural resources- air, water and land

Which of the following is/are damages caused by acid rain?

  1. It depletes the soil of nutrients, increases the acidity of the soil and reduces fertility.

  2. It destroys marine life due to change in pH of the environment.

  3. It causes material damage.

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

The damages caused by acid rain are:

  1. It depletes the soil of nutrients, increases the acidity of the soil and reduces fertility, as the ideal conditions for the growth of trees are lost. 
  2. It destroys marine life due to change in pH of the environment, making it unfit for habitation by aquatic animals.
  3. It causes material damage such as corrosion of marbles.