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 evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

Which of the following can replenish nutrients in the soil?

  1. Fertilizer

  2. Manure

  3. Compost

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

There are different methods by which nutrients in the soil can be replenished. Fertilizers and manures contain plant nutrients such as nitrogen, phosphorus, potassium. Fertilizer can be added to the soil. It helps in replenishing exhausted soils with rich sources of organic nutrients. Manure is environment friendly and replenishes the soil with organic nutrients. Compost is decomposed organic material. It reintroduces living organisms and nutrients in the soil. It improves soil structure and provides a healthy environment for plant roots. 

Thus, the correct answer is 'All of the above.'

Multiple choice evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

Bio-fertiliser which makes available phosphorus is?

  1. Azolla

  2. Aulosira

  3. Mycorrhiza

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

Mycorrhizal fungi, which form a symbiosis with the roots of nearly all vascular plants, play a key role in solving the phosphate shortage problem for plants. Mycorrhizal fungi can effectively increase phosphate uptake by converting insoluble phosphates to soluble, available forms.

So, the correct option is 'Mycorrhiza'.

Multiple choice evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

Biofertilizers are preferred over chemical fertilisers because

  1. They are cheap

  2. They do not cause pollution

  3. They are harmful

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Biofertiliser are preferred over chemical fertilisers because they contain organic materials while fertilisers contain chemical substances that when used in excess become harmful to the consumers. Continuous application of fertilisers to the soil decreases its fertility and also leads to increase in the acidity of the soil. Also the fertiliser runoff from the fields also causes water pollution. Cyanobacteria such as Anabaena and Nostoc also fix atmospheric nitrogen and act as bio-fertilisers especially in paddy fields.
So the correct option is 'They do not cause pollution' .
Multiple choice evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

Biofertilizers increase the _________ content of the soil.

  1. Nutrient

  2. Humus

  3. Water

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

Biofertilizer is a substance that contains living organisms which is used to increase the fertility of the soil. It improves the growth of plant by increasing the content of the soil and thereby increasing the availability of nutrients to the host plant. Also, it does not allow pathogens to flourish. Various biofertilizers are Rhizobium, Azotobacter, blue green algae (BGA). They live in symbiotic association with the plants and provides nitrogen to the plant. 

Thus, the correct answer is option A.

Multiple choice evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

Cow dung that is used as a fertilizer can be replaced by 

  1. Insecticides.

  2. Pesticides.

  3. Biofertilizers.

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

Traditionally, cowdung is used as a fertilizer. It provides growing medium for plants. It is nutrient-rich fertilizer. It is either mixed into the soil or used as top dressing. However, methane (greenhouse gas) is emitted from cowdung when it is processed. Hence, it is replaced by biofertilizers. Biofertilizers are substances which contains live organisms and are used to increase fertilizer of the soil. Examples of biofertilizers include rhizobium, azotobacter, azospirillum and blue green algae(BGA).

Thus, the correct answer is option C.

Multiple choice evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

Which of the following plants are used as green manure in crop field and in sandy soils?

  1. Crotalaria juncea and Alhagi camelorum

  2. Calotropis procera and Phyllanthus niruri

  3. Saccharum munja and Lantana camara

  4. Dichanthium annulatum and Azolla nilotica
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Crotalaria juncea and Alhagi camelorum are used as green manure in crop fields and sandy soils because these plants, when grown, replenish the soil with sufficient nutrients and nitrogen content after its usage by the crop plant.

So, the correct option is 'Crotalaria juncea and Alhagi camelorum'.

Multiple choice evs a seeds tells a farmer's story manure manures and fertilisers water absorption organ

Which of the following can differentiate chemical fertlizers from natural fertilizers?

  1. Chemical fertilizer is soluble but not natural fertilizer.

  2. Natural fertilizer is nutrient specific but not chemical fertilizer.

  3. Chemical fertilisers can affect the pH of the soil while natural fertilisers do not affect the pH of the soil.

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

  • Those fertilizers which get decomposed naturally are known as natural fertilizers whereas those which are human-made are known as chemical fertilizers. 
  • Natural fertilizers include compost, animal waste, dead organisms, etc. Chemical fertilizers include inorganic materials. 
  • Chemical fertilizers are directly available whereas natural fertilizers need to be prepared. Chemical fertilizers contain different chemical so they affect the pH value of soil whereas natural fertilizers don't.

So, the correct option is 'Both A and C'.

Multiple choice zoology living and non living characteristics of life attributes of living organisms signs of life biology : an introduction living world and classification

Which of the following helps in decomposition in soil and increases its nutrient content in the soil?

  1. Fungi

  2. Virus

  3. Protozoa

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

Fungi feed by saprophytic mode of nutrition on dead and decaying plants and animals. In this, the fungi release enzymes on the dead organism and break down complex substances into simpler substances. They absorb the required amount of released nutrients and release the rest in the soil hence increase its nutrient content.

So, the correct answer is 'Fungi'.

Multiple choice chemistry nitrogen and sulfur nitrogen gas component of air - nitrogen nitrogen

$\mathrm{A}$ nitrogenous fertilizers having more nitrogen is :

  1. $(\mathrm{N}\mathrm{H} _{4}) _{2}\mathrm{S}\mathrm{O} _{4}$
  2. $Ca(NO _{3}) _2$
  3. $NH _{2}CONH _{2}$
  4. $NH _4NO _3$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Percentage of $N _2$ in following compounds is calculated by formula 
$(atomic weight of N _2 in compound / Atomic weight  the compound)\times100$
So, percentage of $N _2$ in compounds is given as
In ${(NH _4)} _{2}SO _4$ it is 21%
In $Ca{(NO _3)} _{2}$ it is 17%
In $NH _2CONH _2$ it is 47%
In $NH _4NO _3$ it is 35%.

Multiple choice chemistry nitrogen and sulfur nitrogen gas component of air - nitrogen nitrogen

What is the key element in soil fertilizer?

  1. Carbon

  2. Nitrogen

  3. Oxygen

  4. Neon

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

Nitrogen is the key element in soil fertilizer. It is essential for plant growth but plants cannot utilize atmospheric nitrogen as it is inert due to presence of triple bond. Hence, it is supplied through fertilizer.

Multiple choice chemistry nitrogen and sulfur nitrogen gas component of air - nitrogen nitrogen

Soil fertilizer contains ______ as a key element.

  1. carbon

  2. nitrogen

  3. oxygen

  4. neon

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

Soil fertilizer contains Nitrogen as a key element.
Nitrogenous fertilizers react with moisture in the soil and produce ammonia which is converted to nitrates by soil bacteria and stored as plant food.

Multiple choice chemistry nitrogen and sulfur nitrogen gas component of air - nitrogen nitrogen

Which of the following is not a nitrogenous fertilizer ?

  1. Calcium cyanamide

  2. CAN

  3. Super phosphate of lime

  4. Urea
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Calcium cyanamide ($CaCN _2$) is nitrogenous fertilizer.
CAN is calcium ammonium nitrate and urea $NH _2-CO-NH _2$ is also nitrogenous fertilizer.
Superphosphate of lime, $Ca(H _2PO _4) _2$ is fertilizer of phosphorous.So it's not the fertilizer of nitrogen.
Hence option C is correct.
Multiple choice zoology ecosystems decomposition in ecosystem ecosystem productivity and decomposition producers, consumers and decomposers

.......... play a very important role in  decomposition of organic matter in the soil

  1. Cat

  2. Plants

  3. Microorganisms

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

Micro-organisms dwell in soil. They contribute to various processes related to the soil, plants and atmosphere. One of the processes is decomposition of dead remains of plants and animals

So, the correct answer is 'micro-organisms'