Agriculture Chemistry Questions and Answers
1. Specific heat of quartz among the different soil constituents is
(1) Lowest
(2) Highest
(3) similar to other constituents
(4) variable
2. The pF value of saturated soil and oven dry soil is
(1) 0 and 14
(2) 0 and 7
(3) 1 and 14
(4) 1 and7
3. The available water retained in soil is between
(1) 0 to 3 bar
(2) -1 to -1/3 bar
(3) 15 to 30 bar
(4) -1/3 to -15 bar
4. At field Capacity the moisture is held with soil water potential
(1) <1 bar
(2) <0.5 bar
(3) <1/3 bar
(4) > 1/3 bar
5. In gravimetric method of soil moisture measurement, the Soil is oven dried at
(1) 90° – 100 °C
(2) 105° – 110°C
(3) 115°- 120 °C
(4) 125° – 130 °C
6. Which of the following method of measurement of soil moisture is considered as check for all other methods?
(1) Electrical conductivity method
(2) Tensiometer method
(3) Gravimetric method
(4) Neutron probe method
7. Estimate the percent moisture in a given:
Weight of moist soil + box = 200 gm
Weight of oven dry soil + box = 160 gm
Weight of empty box — 50 gm
(1) 22.22%
(2) 40.60%
(3) 36.36%
(4) 36.84%
8. If wire is formable but soil mass is easily deformable, then the soil is
(1) Non-plastic
(2) Plastic
(3) Slightly plastic
(4) Very plastic
9. Moisture content of soil at a point where the soil water mass flows under an applied force and fails to retain its shape is called
(1) plastic index
(2) non-plastic
(3) lower plastic limit
(4) upper plastic limit
10. Presence of silica, lime and other salts in soil, the colour of soil appears like
(1) dark coloured
(2) brown coloured
(3) red coloured
(4) light coloured
11. Presence of organic matter and iron oxides in the soil, the colour of soil appears like
(1) red colour
(2) brown colour
(3) dark colour
(4) yellow, red colour
12. Which of the following represents the purity or strength of colour in Munsell colour chart?
(1) Hue
(2) Value
(3) Chroma
(4) Hue and Value both
13. Identify the 1:1 clay mineral of soil among the following:
(1) Vermiculite clay
(2) Kaolinite clay
(3) Montmorillonite clay
(4) Chlorites clay
14. In case of degraded alkali soil, there is a leaching of saline — sodic soil occurs and part of exchangeable Na is frequently replaced by
(1) Ca++
(2) Mg++
(3) H+
(4) K+
15. The soils having EC < 4 ds/m, ESP > 15 and pH more than > 8.5 the soils is
(1) Saline
(2) Alkali
(3) Saline alkali
(4) Degraded alkali
16. Soils having Grey brown upper crust and are hard on walking are known as
(1) Saline soil
(2) Saline alkali soil
(3) Sodic soils soil
(4) Normal soils soil
17. The saline and alkali soils fall in which order?
(1) Entisol
(2) Alfisol
(3) Molisol
(4) Aridisol
18. The saline and alkali soils fall in which soil order?
(1) Orthids and Argids
(2) Albolls and Xerolls
(3) Aqualts and Humults
(4) Andepts and Ochrepts
19. The boron concentration (mg/kg) unsafe for plant growth
(1) > 1.5 mg/kg
(2) 0.75 — 1.5 mg/kg
(3) 0.7-0.25 mg/kg
(4) <0.2 mg/kg
20. The amount of iron sulphate (FeSO4 – 7H2O) in tons is equivalent to 1.0 ton (one ton) of gypsum to improve soil
(1) 1.0 ton
(2) 0.57 ton
(3) 1.62 ton
(4) 0.80 ton
Practice Papers for Agriculture Students
21. The irrigation water contains CO3—HCO3-, Ca++ and Mg++ ion 1, 4, 2.5 & 1.5. Calculate the RSC in irrigation water (mcl-1).
(1) 0.1
(2) 10
(3) 0.01
(4) 1.0
22. The nutrient index value: Area with nutrient index value is > 2.3, then
(1) High
(2) Medium
(3) low
(4) low medium
23. Diagnosis and Recommendation Integrated System (DRIS) approach was provided by
(1) Mitectierlich’s
(2) Beaufils
(3) Liebig’s
(4) Wallace
24. Name the enzyme responsible for reducing nitrogen (N2) to ammonia (NH3).
(1) Peptase
(2) Urease
(3) Nitrogenase
(4) Amylase
25. If azolla is grown in rice field along with rice crop, then how much nitrogen is fixed by azolla in rice field?
(1) 10-20 kgN/ha
(2) 20-30 kgN/ha
(3) >50 kgN/ha
(4) 30-40 kgN/ha
26. Which legume crop fix highest N (kg N/ha/year)?
(1) Groundnut
(2) Cow pea
(3) Clover
(4) Alfalfa
27. The process of conversion of organic form to inorganic form (mineral form) of nutrient element is called
(1) Nitrification
(2) Denitrification
(3) Mineralization
(4) Volatilization
28. The processes of reduction of NO3- to N2 or N2O mediate by micro-organism is known as
(1) Mineralization
(2) Nitrification
(3) Denitrification
(4) volatilization
29. The bacteria responsible for oxidizing Fe2+ — Fe3+ (ferrous to ferric form) under acidic environment
(1) Pseudomonas
(2) Thiobacillus
(3) Lactobacillus
(4) Orthobacter
30. Vascular Arbuscular Mycorrhiza (VAM) increase uptake of
(1) Fe
(2) Cu
(3) Zn
(4) Ni
31. Identify the microb which have also control the plant disease.
(1) Thiobacillus
(2) Lactobacillus
(3) Pseudomonas
(4) Orthobacter
32. The highest enzymatic activity is observed in which type of soil particle (clay size)?
(1) clay 50 — 70 p (Mue)
(2) clay < 50 p (Mue)
(3) clay 70-90 µ
(4) clay <90 µ
33. Solubility of gypsum is
(1) 5%
(2) 50%
(3) 0.25%
(4) 0.10%
34. The Sulphur (S) content in pure gypsum is
(1) 21%
(2) 23%
(3) 26%
(4) 16%
35. The Zn content in ZnSO4 (Zinc sulphate)
(1) 21%
(2) 23%
(3) 20%
(4) 16%
36. Farm Yard Manure (FYM) have N, P2Os and K2O approximately
(1) 1.0, 0.6 and 1.0%
(2) 2.0, 1.0 and 0.5%
(3) 0.5, 0.2 and 0.5%
(4) 3.0, 2.0 and 1.0%
37. Deficiency of N in plant causes yellowing of
(1) upper leaf
(2) lower leaf
(3) middle leaf
(4) whole plant
38. Biological Nitrogen Fixation (B.N.F.) is catalized by
(1) Cu
(2) Zn
(3) B
(4) Mo
39. Due to deficiency of Zn causes Khaira disease in rice field, the disease caused of rice field appear
(1) Necrotic
(2) yellow coloured
(3) copper brownish coloured
(4) reddish coloured
40. Nutrient deficiency of which nutrient causes chlorosis and stunted growth:
(1) Na
(2) Cl
(3) Mo
(4) N
41. Which nutrient stimulate the root growth of plant?
(1) N
(2) P
(3) K
(4) Mn
42. Which of the following nutrient impart resistance to plants against fungal and bacterial diseases?
(1) N
(2) P
(3) K
(4) Ca
43. Which of the plant nutrient is constituent of cell wall and essential to stability to cell membrane?
(1) N
(2) K
(3) Zn
(4) Ca
44. Which of the following nutrient is constituent of chlorophyll and chromosome?
(1) N
(2) Mg
(3) Ca
(4) K
45. In which type of soil Olsen’s method for phosphorus determination is used?
(1) Acidic soil
(2) Saline soil
(3) Neutral and calcareous soil
(4) Degraded alkali soil
46. Extraction of P by Brays method is done by
(1) NaHCO3
(2) NH4F
(3) NH4Cl
(4) Na2CO3
47. The DTPA extractant concentration is used to determine micro-nutrients
(1) 0.0005 M
(2) 0.05 M
(3) 0.005 M
(4) 0.5 M
48. The (KCl) murate of potash is not suitable for tobacco and potato because of
(1) Cl toxicity
(2) K toxicity
(3) costly fertilizer
(4) not readily available
49. Which type of soils are covering largest area of India?
(1) Laterite soil
(2) Deseret soil
(3) Alluvial soils
(4) Black cotton soils
50. The micro-organism (bio-fertilizer) grows at the temperature 20 °C to 40 °C are called
(1) Thermophile
(2) Mesophile
(3) Psycrophile
(4) Hyper thermophile
51. Amount of NPK in poultry manure:
(1) 0.5 0.3 0.5%
(2) 3.0 1.0 2.0%
(3) 3.0 2.5 1.5%
(4) 0.7. 1.5 1.2%
52. Bone is rich source of
(1) P only
(2) P and Ca
(3) N and K
(4) P and Mg
53. The CaCO3 is commonly absent in the soils having pH
(1) <7.0
(2) > 7.0
(3) <8.4
(4) >8.4
54. The dominant mineral of sand, fine sand and course silt soils
(1) Pyroxine
(2) Mica
(3) Feldspar
(4) Quartz
55. Conversion factor of organic carbon to organic matter
(1) 1.720
(2) 1.750
(3) 2.205
(4) 1.724
56. Walkley & Black method is used to determine
(1) N2
(2) K2O
(3) OC
(4) P2O5
57. High amount of K2O (Potash) in the soil indicate the presence of
(1) Illite
(2) Vermiculate
(3) Chlorite
(4) Montmorillonite
58. What is the normality of concentrated hydrochloric acid (AR grade) in general?
(1) 40
(2) 30
(3) 10
(4) 20
59. Available phosphorus (Olsen’s method) and available potassium extracted from soil in laboratory respectively
(1) Sodium acetate and NaHCO3
(2) Na2CO3 and Morgan reagent
(3) NaHCO3 and acetic acid
(4) NaHCO3 and Morgan’s reagent
60. Laboratory method of — sulphur identification in soil is
(1) Olsen’s method
(2) Walkley and black method
(3) Turbidity method
(4) Alkaline permanganate method
61. Excesses of phosphorus in soil may cause deficiency of which micro-nutrients?
(1) Cu & Ni
(2) Fe & Zn
(3) Mn & B
(4) Ni & Cd
62. The alkaline potassium permanganate method (Alk. KMnO4) for determination of available nitrogen (N) in soil was given by
(1) Olsen
(2) Bray
(3) Subbiah and Asija
(4) Subbiah and Makhiya
63. The determination of micro-nutrients on atomic absorption — spectro photometer by DTPA was given by
(1) Walkley and Black
(2) Lindsay and Norwell
(3) Bray’s
(4) Olsen’s
64. The case of replacement of Ca2++ from colloids by plant uptake varies in order:
(1) Kaolinite > Hlite > Montmorillonite > Peat
(2) Montmorillonite > Peat > Kaolinite > Illite
(3) Peat > Kaolinite > Illite > Montmorillonite
(4) Peat > Illite > Kaolinite > Vermiculite
65. If the Exchangeable Sodium Ratio (SAR) of given soil is 25.0, then calculate the ESR.
(1) 0.398
(2) 0.375
(3) 0.425
(4) 0.596
66. The exchangeable sodium ratio is 0.39, then ESP of the soil will be
(1) 36%
(2) 26%
(3) 32.0%
(4) 40.0%
67. If requirement of 10 T gypsum is needed to amend the soil, then element sulphur will be required
(1) 0.8 T
(2) 1.8 T
(3) 2.8 T
(4) 2.0 T
68. Carbon (C), Hydrogen (H) and Oxygen (O) constitute about in plants
(1) 95-96%
(2) 80-85%
(3) 90-95%
(4) 85-90%
69. The N concentration in N sufficient plant varies:
(1) 0.1-0.5%
(2) 1-5%
(3) 0.5-1%
(4) 5-7%
70. The nutrient element regulate the opening and closing of stomata and transformation of nutrients?
(1) N
(2) P
(3) Ca
(4) K
71. Sulphur containing amino acids in mustard are
(1) Auxines
(2) Cysteine, Cystine and Phytines
(3) Cysteine, Cystine and Methionine
(4) Cysteine, Methionine and Auxines
72. If 12k cal energy is accumulated in two pyrophosphate bond, then which molecule stores that energy?
(1) ADP
(2) ATP
(3) C6H12O6
(4) Ketones
73. Mn deficiency causes
(1) Grey speck of oat
(2) Speckled yellow of sugar beet
(3) Marsh spot of pea
(4) All of these
74. The relationship among the Field Capacity (FC), wilting point and Available Water Capacity (AWC) is
(1) FC=AWC – Wilting Point (PWP)
(2) AWC =FC-PWP
(3) PWP=FC-AWC
(4) AWC =PWP-FC
75. The Redox potential Eh of Fe+3 to Fe+2 at which change in form occur?
(1) 0.18 to 0.15
(2) 0.38 to 0.32
(3) 0.20 to 0.28
(4) 0.28 to 0.22
76. The Nomenclature of soil is typic hyper thermic ustipssment is, then the ustic stand for
(1) temperature regime
(2) textural class
(3) moisture regime
(4) mineral class
77. Heavy metals are accumulated in higher (large amount) amount when irrigated with untreated sewage
(1) Wheat seeds (grains)
(2) Barley seeds (grains)
(3) Mustard seeds
(4) Leafy vegetables
78. Tannery and textile industrial effluents are characterized by
(1) High BOD, COD
(2) Low BOD, COD
(3) Medium BOD, COD
(4) High COD
79. Tannery is treated with chromium (Cr) which form of chromium is more hazardous to animal and human being
(1) Cr2+
(2) Cr3+
(3) Cr6+
(4) None of these
80. Metal finishing industries effluents are rich in which heavy metals?
(1) Cr and Ni
(2) Zn and Fe
(3) Cu and Pb
(4) Zn and Cu
81. Blue baby syndrome is caused by excesses presence of
(1) Cd
(2) NO3
(3) Pb
(4) Ni
82. The itai-itai disease is caused by higher content of which heavy metal in rice?
(1) Pb
(2) Ni
(3) Cd
(4) Cr
83. Nuclear Power Plant accident took place which place in then USSR causing great hazard to agricultural soil and aquatic life:
(1) Beiying
(2) Moscow
(3) Chernobyl
(4) Kieve
84. Which of the following is not result of eutrophication?
(1) accumulation of algae
(2) high aquatic plant/fish mortality
(3) detrimental change in water quality
(4) Improving the water quality and good eco system.
85. Which of the following gas (green house gas) contribute around 6.0% to the anthropogenic green house effect?
(1) N2O
(2) CO2
(3) SO2
(4) NH3
86. The relation between Osmatic Pressure (bar or atmosphere) and electrical conductivity for salt mixture is OP = 0.36 x EC, the EC is expressed as in MKS system
(1) ds/m
(2) mhos/cm
(3) µ mhos/cm
(4) µ mhos/cm
87. The safe limit of Residual Sodium Carbonate (R.S.C.) me/l for the plant growth is?
(1) <1.25 mc/l
(2) <2.5 mc/l
(3) <4.0 mc/l
(4) >4.0 mc/l
88. What will be the Leaching Requirement (L.R.) of the given irrigation water having EC 4 ds/m when EC of drainage water is 10 ds/m?
(1) 20.5%
(2) 35.4%
(3) 40.0%
(4) 40.3%
89. With the increase in organic matter of the given soil the Particle Density (P.D.)?
(1) Does not change (No change)
(2) Increases
(3) First decreases and then increases
(4) Decreases
90. Tron and aluminium oxides and hydroxides are the colloidal material of which of the following nature?
(1) Slowly reversible
(2) Slowly irreversible
(3) Reversible
(4) Irreversible
91. Specific heat may be defined as the amount of heat required to raise the temperature of one gram substance by
(1) 1°F
(2) 1°K
(3) 1°C
(4) 0.1°F
92. The heat capacity of given material is equal to its specific heat
(1) divided by the mass of given material
(2) added by the mass of given material
(3) multiplied by the mass of given material
(4) subtracted by the mass of given material
