Agricultural Engineering

August 2024

Elements of Soil Science - Past Questions - 2061 Baishakh

TRIBHUVAN UNIVERSITY
INSTITUTE OF ENGINEERING
Examination Control Division
2061 Baishakh

Exam: Regular/Back
Level: B.E.
Programme: B. Agri.
Year / Part: II / I
Subject: Elements of Soil Science
Full Marks: 80
Pass Marks: 32
Time: 3 hrs.

Candidates are required to give their answers in their own words as far as practicable. Attempt any five questions. The figures in the margin indicate Full Marks. Assume suitable data if necessary.

a) Describe the physical properties of colloids. How do soil colloids influence the availability of nutrients for plant use? [8]
b) What is meant by cation and anion exchange capacity? Describe the significance of cation exchange capacity in agricultural soils. [8]
a) Describe the causes and consequences of alkalinity and salinity of soils. What are the options to correct soil salinity? [8]
b) Explain the role of primary soil nutrients in crop production. Describe the deficiency symptoms of nitrogen in plants. [8]
a) What is soil aggregation? Explain the stages and processes of the formation of water-stable soil aggregates. [8]
b) Why is soil texture considered a fundamental soil property? Explain the purpose of determining soil texture. [8]
a) Explain the pattern of extraction of soil moisture by the root system of crop plants. Describe the working principle of a soil moisture meter. [8]
b) What are the causes of poor soil aeration? Explain the ways and means of managing aeration in soils. [8]
a) What is the difference between regolith and soil? Explain the process of soil formation. [8]
b) Explain the procedure for determining soil texture by the hydrometer method. [8]
Write short notes on any four: [4 × 4]
a) Nitrification and Denitrification
b) Green Manuring
c) Secondary Plant Nutrients
d) Soil Profile
e) Infiltration Rate

Old question Past question Questions collections Second year Soil Science Third semester

Elements of Soil Science - Past Questions - 2069 Chaitra

RIBHUVAN UNIVERSITY
INSTITUTE OF ENGINEERING
Examination Control Division
2069 Chaitra

Exam: Regular
Level: BE
Programme: B. Agri.
Year / Part: II / I
Subject: Elements of Soil Science (AE502)
Full Marks: 80
Pass Marks: 32
Time: 3 hrs.

✓ Candidates are required to give their answers in their own words as far as practicable. Attempt all questions.
✓ The figures in the margin indicate Full Marks.
✓ Assume suitable data if necessary.

What are the differences between land and soil? Describe the pedological concept of soil science. [2 + 2]
What are the soil-forming minerals? Give examples. [4]
Discuss in brief the factors of soil formation. [8]
What do you mean by weathering of rocks? Describe in brief the types of weathering. [2 + 6]
What are the differences between soil texture and soil structure? List out the significance of soil texture from an agricultural point of view. [3 + 5]
A soil sample of 100 cc weighs 165 gm. After oven drying, the weight of the sample was found to be 150 gm and the volume was measured to be 60% of the initial volume. Calculate the bulk density, particle density, and porosity of the soil. [6]
Explain the significance of soil temperature in agriculture. [4]
What is the difference between infiltration and percolation? Define field capacity and wilting point. [3 + 3]
Write a short note on the soil moisture characteristic curve. [4]
What do you mean by acidic soils, saline soils, and alkaline soils? [6]
Write down the main functions of each of the macro plant nutrients (N, P, K). [4]
Write down the deficiency symptoms of macro plant nutrients. [6]
Give two examples of inorganic fertilizers with their composition and uses. [4]
Write a short note on FYM (Farm Yard Manure) and compost. [4]
Why are green manures more preferred than inorganic fertilizers? [4]

Old question Past question Questions collections Second year Soil Science Third semester

Elements of Soil Science - Past Questions - 2066 Bhadra

TRIBHUVAN UNIVERSITY
INSTITUTE OF ENGINEERING
Examination Control Division
2066 Bhadra

Exam: Regular/Back
Level: BE
Programme: B. Agri.
Year / Part: II / I
Subject: Elements of Soil Science
Full Marks: 80
Pass Marks: 32
Time: 3 hrs.

Candidates are required to give their answers in their own words as far as practicable. Attempt any five questions. All questions carry equal marks. Assume suitable data if necessary.

a) Define soil in relation to agricultural production. Explain the factors affecting soil formation.
b) Write an essay on the weathering of rocks and minerals.
a) What is a soil profile? Describe soil master horizons.
b) Define bulk density, particle density, and porosity. Classify soil according to texture.
a) Enlist different methods of soil water measurement. Write an essay on the principle of the field tensiometer.
b) Define infiltration and infiltration rate. Describe the factors affecting soil infiltrability.
a) What do you mean by cation and anion exchange? Describe in detail the cation exchange capacity.
b) Describe macro and micro nutrients. Explain the role and deficiency symptoms of phosphorus in plants.
a) Describe the methods of soil fertility evaluation. Discuss in detail the process of soil test method up to fertilizer recommendation.
b) What are soil colloids? Discuss their properties.
Write short notes on (any four):
a) Green manuring
b) Soil temperature
c) Soil moisture characteristics curve
d) Process of soil survey and mapping
e) Soil reaction

Old question Past question Questions collections Second year Soil Science Third semester

Elements of Soil Science - Past Questions - 2070 Chaitra

TRIBHUVAN UNIVERSITY
INSTITUTE OF ENGINEERING
Examination Control Division
2070 Chaitra

Exam: Regular
Level: B.E.
Programme: B. Agri.
Year / Part: II / I
Subject: Elements of Soil Science (AE502)
Full Marks: 80
Pass Marks: 32
Time: 3 hrs.

✓ Candidates are required to give their answers in their own words as far as practicable.
✓ Attempt All questions.
✓ The figures in the margin indicate Full Marks.
✓ Assume suitable data if necessary.

How does soil differ from land? Describe the Edaphological concept of soil science.
[2 + 2]
What are the types of minerals found in soil? Explain briefly the weathering processes of rocks and minerals.
[2 + 4]
What do you mean by soil morphology? Describe the soil formation factors.
[2 + 6]
Why is the classification of soil necessary? Write briefly the features of soil temperature regimes.
[2 + 4]
What are the soil attributes and environmental conditions of brown to black color in soil? Which texture of soil do farmers prefer and why?
[2 + 4 + 3]
Describe the feel method of determining soil texture. Explain briefly the types of soil structure.
[7]
Why is it necessary to determine the bulk density of soil for an agriculturist? A soil sample was taken with the help of a core cutter with an internal diameter of 10 cm and a height of 13 cm. The initial weight of soil was 1.5 kg and the oven-dry weight was found to be 1.3 kg. Determine the bulk density of the soil.
[2.5 + 1.5]
Write down the significance of soil temperature in relation to agriculture. What are the effects of poor soil aeration?
[2 + 4]
How will you control excess temperature in soil? Write down the reasons for poor aeration.
[2 + 2]
Define soil moisture, infiltration, and percolation. Write down the importance of the soil moisture curve in agricultural engineering.
[2 + 4]
What are macronutrients? What are the roles of nitrogen in plants? Write down the symptoms of nitrogen deficiency.
[2 + 2]
Define soil pH. How can you determine soil pH in the laboratory? What type of treatment can be applied to acidic soil?
[1 + 3]
What do you mean by soil organic matter? Why is it necessary for plants? How do you determine soil organic matter in the laboratory?
[1 + 2 + 3]
What do you mean by complete and incomplete fertilizer? Explain with examples. What are the advantages and disadvantages of inorganic fertilizers?
[2 + 2]
What is a soil colloid? What are the roles of soil colloids? What are the sources of charges on soil colloids?
[1 + 2]

Old question Past question Questions collections Second year Soil Science Third semester

Elements of Soil Science - Past Questions - 2061 Poush

TRIBHUVAN UNIVERSITY
INSTITUTE OF ENGINEERING
Examination Control Division
2061 Poush

Exam: Back
Level: B.E.
Programme: B. Agri.
Year / Part: II / I
Subject: Elements of Soil Science
Full Marks: 80
Pass Marks: 32
Time: 3 hrs.

✓ Candidates are required to give their answers in their own words as far as practicable.
✓ Attempt any Five questions.
✓ All questions carry equal marks.
✓ Assume suitable data if necessary.

1.
a) What are the general properties of soil colloids? Explain different types of soil colloids.
b) What are the advantages and limitations of soil tests as a guide to determine the kinds and rates of fertilizers to be used?

2.
a) Describe different forms of lime. Explain the role and action of lime in reducing soil acidity.
b) Nitrogen in the soil is fixed from the atmosphere, and it is also fixed by vermiculite clays and humus. Differentiate between these two processes of nitrogen fixation and explain the role played by microbes in each of the two processes.

3.
a) How are the edaphological views different from pedological views in the study of soils? Explain the process of soil formation.
b) Why are well-aggregated soils considered good for plant growth? Explain the process of aggregation in soils.

4.
a) What is soil moisture tension? Explain the purpose of preparing a soil moisture characteristic curve.
b) Differentiate between soil texture and soil structure. What behaviors of soils are controlled by soil texture?

5.
a) Explain the significance of soil temperature. What factors control the variation of soil temperature in the soil profile?
b) What are the causes of poor soil aeration? What are the consequences of poor soil aeration in crop production?

6.
Write short notes on any four of the following:
a) Phosphorus cycle
b) Anion exchange capacity
c) Soil pH
d) Dispersion and flocculation
e) Plough pan and traffic pan