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 zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

Biofertilizer is?

  1. Manure

  2. Enriched manure

  3. Nutrient rich organisms

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

A biofertilizer is a substance which contains nutrient rich living microorganisms which colonize the rhizosphere or the interior of the plant and promotes the growth of the plant or the seed by increasing the availability of primary nutrients to the plant.

Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

Vesicular arbuscular mycorrhizae (VAM) are important in

  1. Nitrate uptake

  2. Phosphate uptake

  3. Both A and B

  4. Sulphate uptake
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
An arbuscular mycorrhizal (AM) fungus is a type of mycorrhiza characterized by the formation of unique structures, arbuscules and vesicles. VAM fungi help plants to capture nutrients such as phosphorus, nitrogen and micronutrients from the soil. Vesicular-arbuscular mycorrhizae are important in helping the plant's nitrate and phosphate uptake. 
Thus, the correct answer is option C.
Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

Biofertilizers are

  1. Any free living soil bacteria

  2. Fertilizers formed by ploughing in legumes

  3. Fertilizers obtained by decay of dead organisms

  4. Fertilisers prepared by mixing cattle dung with crop residues
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Biofertilizers are the suspension of microorganism which is formed by ploughing in legumes. They enrich the nutrient quality of the soil. The main sources of biofertilizers are bacteria, fungi, and cyanobacteria (blue-green algae). Biofertilizers will help solve such problems as increased salinity of the soil and chemical run-offs from the agricultural fields.

So, the correct answer is option B.

Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

A green manure supplies

  1. Organic matter

  2. Additional nitrogen

  3. Protect soil against erosion and leaching

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

Green manure acts mainly as soil acidifying matter to decrease the alkalinity/pH of alkali soils by generating humic acid and acetic acid. The root systems of some varieties of green manure grow deep in the soil and bring up nutrient resources unavailable to shallower-rooted crops. Erosion control is often also taken into account when selecting which green manure cover crop to plant.

So, the correct answer is option D.

Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

Sesbania rostrate is preferred as green manure over other species because.

  1. It grows quickly

  2. It has extensive root system

  3. It possesses nodules on both stem and roots

  4. It possesses leaf nodules
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Sesbania rostrate is mainly used as green manure to improve the fertility of the soil due to its fast growth, high biomass production and the ability to convert atmospheric nitrogen into a usable form for plants.

Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

Consider the following statements.
Mycorrhizal biotechnology has been used in rehabilitating degraded sites because mycorrhiza enables the plants to.
a. Resist drought and increase absorptive area
b. Tolerate extremes of pH.
c. Resist disease infestation
Of these statements.

  1. $2$ and $3$ are correct
  2. $1$ and $2$ are correct
  3. $1$ and $3$ are correct
  4. $1, 2$ and $3$ are correct
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

Azolla gives a good biofertilizer when mixed with

  1. Bone-meal

  2. Cowdung

  3. Blue-green algae

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

BGA and Azolla have known to be used for the rice cultivation and they are very good for increasing the crop yield and productivity as they supply the soil and the plant with enough nitrogen. They are known used together as the biofertilizers.


So, the correct option is 'Blue-green algae'

Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

If wheat field is inoculated with Rhizobium, then

  1. Soil will become nitrogen rich

  2. No effect on soil nitrogen

  3. Soil will be depleted of nitrogen

  4. Soil will become rich in calcium
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Rhizobium is an important symbiont for legumes but it plays an important role with nonlegumes by producing growth hormones. When wheat is inoculated with Rhizobium, no effects are observed in terms of growth and yield, which indicates that uptake of soil nitrogen is not seen as in legumes.

So, the correct answer is option B.

Multiple choice evs louis pasteur contribution of louis pasteur discoveries by louis pasteur discovery of microorganisms

The method of growing micro-organisms as a thin layer on a nutrient medium is known as

  1. Thin layer growth system

  2. Support growth system

  3. Suspended growth

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

Support growth system refers to a process in which the microorganisms are grown on a thin layer of nutrient medium. A nutrient medium provides various nutrients required for the growth of microorganism to carry out their metabolic activities. The nutrient media supports the growth of a wide range of microorganisms. So, the correct answer is 'Support growth system'.

Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

Farmers of a particular region are concerned that premature yellowing of leaves of pulse crop might cause decrease in the yield. Which treatment could be beneficial to obtain maximum seed yield?

  1. Application of iron and magnesium to promote chlorophyll synthesis

  2. Frequent irrigation of crop

  3. Treatment of plants with cytokinins along with a small dose of nitrogen fertilizer
  4. Removal of all yellow leaves and spraying the remaining green leaves with $2, 4, 5-$T
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cytokinins promote cell division and delay senescence (yellowing) in leaves, while nitrogen is essential for chlorophyll synthesis, helping to maintain green leaves and improve yield in pulse crops.