Environmental Studies · Biology

Soil Science and Fertilizers

1,509 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

Which of the following materials of biological origin are commonly used to maintain and improve soil fertility?

  1. Green manure

  2. Biofertilizers

  3. Bioinsecticides

  4. Both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Green manure and biofertilizers maintain and improve soil fertility. Green manure is prepared by the waste leaf from the plants. The waste leaf of the plant is mainly dumped in the soil which is further decomposed by bacteria of the soil.

Biofertilizers are prepared by the strains of microorganism which fix the essential nutrients for the soil.
So, the correct answer is option D.

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

Among the given options, which one is not correct for the use of large amount of fertilisers and pesticides?

  1. Fertilisers are eco-friendly.

  2. Fertilisers turn the fields barren after some time.

  3. Fertilisers remove the useful component from the soil.

  4. Fertilisers destroy the soil fertility.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Pesticides and fertilizers are the chemically synthesized compound used for agriculture purpose. The use of pesticides and fertilizers over a long period of time can destroy soil fertility or soil structure by killing the soil microorganism that recycles nutrients in the soil as they are artificial chemical compounds. It also kills earthworms which are instrumental in making rich humus.

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

Among the given options, which one is not correct for the use of a large amount of fertilizers and pesticides?

  1. Fertilizers are eco-friendly.

  2. Fertilizers turn the fields barren after some time.

  3. Fertilizers adversly affect the useful component from the soil.

  4. Fertilizers destroy the soil fertility.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fertilizers and pesticides are composed of chemical components. These chemicals are harmful to the soil and the environment. These fertilizers and pesticides if put in excess degrades the soil fertility and quality by destroying its natural properties. The chemicals from the fertilizers and insecticides make the soil acidic in nature which leads the soil to lose its fertility to become dry and barren. These chemicals also harm the natural soil tillers, decomposers and the organisms that naturally enhance the soil quality and fertility. Therefore adversely affecting the useful components of soil by depleting the natural nutrient of the soil like nitrogen, potassium and phosphorous, etc. Fertilizers cannot be eco-friendly as it harms the soil, water, and environment, unlike biofertilizers which are organic in nature and are eco-friendly too.
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

Which of the following is not true for fertilisers?

  1. They increase the yield.

  2. Their excessive use disturbs the balance of nutrients in soil.

  3. They are generally used in small quantity.

  4. They are environment friendly.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The by-products of fertilizer industries are pesticides and some chemical fertilizers. They are non-biodegradable, so they get accumulated at each trophic level. These mix up with soil and water. From there, these pesticides are absorbed by the growing plants along with water and minerals.
When herbivores eat these, these poisonous chemicals pass into their bodies through the food chain. When carnivores eat herbivores, these pesticides transfer to their bodies. Man being omnivore, eats both plants and herbivores and these gets accumulators into their body.
Thus, pesticides enter the food chain at the producer level and in the process of transfer of food through food chains, these harmful chemicals get concentrated at each trophic level. This is called bio magnification.
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

Which of the following statement is not true for organic manure?

  1. It enhances water holding capacity of soil

  2. It has a balance of all plant nutrients

  3. It provides humus to soil

  4. None of these
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 the microorganism. 
  • Organic manure contains a few nutrients. It enhances the water holding capacity of soil. 
  • This makes more water available to plants. It has a balance of all plant nutrients. It provides humus (organic matter ) to soil. 

Therefore, option D is correct.  

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

NPK denotes

  1. Nitrogen, protein and kinetic

  2. Nitrogen, protein and potassium

  3. Nitrogen, potassium and kinetic

  4. Nitrogen, phosphorus and potassium
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

NPK stands for Nitrogen, Phosphorous and Potassium as this abbreviation has three letters representing the names of the respective elements. It is used as a fertilizer.

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.