RPSC Rajasthan AARO Agricultural Chemistry 2024 Solved Paper (English) — Agri Master Mind
What is the range of bulk density of the fine-textured soils?
Soil structure often occurs in the subsurface horizon in arid and semiarid regions, is -
- Spheroidal
- Platy
- Blocky
- Prismatic
Out of various humic substances, which fraction is the most soluble, being soluble in water, acid and alkali?
- Fulvic acid
- Humic acid
- Humin and Humic acid
- Humin
Which amendment used for sodic soils management has having highest value of Gypsum equivalent?
- Aluminium sulphate
- Gypsum
- Iron sulphate
- Iron pyrite
Low-base saturated soil that has an argillic or kandic horizon but with base saturation (at pH 8.2) of <35% at 2m depth below the surface, qualifies for which soil order?
- Spodosol
- Ultisol
- Andisol
- Alfisol
Match List-I with List-II and choose the correct answer by using the code given below the lists
- (A)-(i), (B)-(ii), (C)-(iv), (D)-(iii)
- (A)-(iv), (B)-(i), (C)-(iii), (D)-(ii)
- (A)-(i), (B)-(ii), (C)-(iii), (D)-(iv)
- (A)-(iv), (B)-(ii), (C)-(iii), (D)-(i)
Remote sensing refers to data collection without
- Camera
- Software
- field visit
- physical contact with the object
In GIS, spatial data represents
- soil porosity
- crop yield values
- location-based information
- Fertiliser recommendation for soil
The Lateritic soils of India are rich in -
- Kaolin clay
- Vermiculite
- Montmorillonite
- Allophane
Zeta potential is
- potential at the equilibrium plane
- potential at the surface of the colloid
- potential at the outer Helmholtz layer
- potential at the slipping plane
What is the “4R” principle in site-specific nutrient management?
- Right source, right rate, right time, right place
- Right rate, right duration, right depth, right place
- Right source, right crop, right duration, right place
- Right source, right row, right time, right place
The indicator used in iodometric titration is -
- Phenolphthalein
- Methyl Red
- Eriochrome Black T
- Starch
Biological process of wastewater treatment, which involves microorganisms to remove BOD and suspended solids is comes under which category of treatment plant?
- Primary
- Secondary
- Advanced
- Tertiary
In general, the thermal conductivity of soil varies in which order?
- Peat > Clay > Loam > Sand
- Loam > Peat > Clay > Sand
- Clay > Peat > Loam > Sand
- Sand > Loam > Clay > Peat
The Mitscherlich equation, also known as Mitscherlich’s Law of Diminishing Returns, was put forward in the year -
According to the Central Pollution Control Board maximum permissible limit of boron for industrial effluent discharge on the land for irrigation is -
A polyvalent anion cannot be used in the determination of anion exchange capacity because of which reasons-combination?
-
-
- and (B)
-
-
- and (B)
- and (B)
-
- and (B)
- and (B)
- and (B)
- (A), (B) and (D)
-
-
- and (C)
-
-
- and (C)
- and (C)
-
- and (C)
- and (C)
- and (C)
- (A), (C) and (D)
The term ‘pH’ was given by -
- D.K. Das
- S.P.L. Sørensen
- Fried and Dean
- Jackson
Essentiality of element Iron was discovered by the scientist -
- Arnon and Stout
- E. Gris
- C. Sprengel
- J.S. McHargue
The rate of respiration can be used as an index of the biological activity of soil. Out of the following, which enzyme is known as a respiratory enzyme?
- Protease
- Dehydrogenase
- Phosphatase
- Arylsulphatase
What is the colour formed by the reaction of Fe with o-phenanthroline in the colourimetric determination of iron?
- Red
- Yellow
- Blue
- Green
Potassium fixation does not occur in soils dominant –
- Vermiculite and illite
- Kaolinite and chlorite
- Quartz and illite
- Gibbsite and montmorillonite
What is the approximate mass percentage of aluminium in the Earth’s crust?
- %
- %
- %
- %
Which of the following humic fractions is insoluble in acid and soluble in alkali and alcohol?
- Humin
- Humic acid
- Fulvic acid
- Hymatomelanic acid
Which mineral weathers faster due to looser oxygen packing?
- Quartz
- Muscovite
- Olivine
- Zircon
The two radioisotopes of phosphorus ( and ) have half-lives respectively -
- and 25.3 days
- and 21.3 days
- and 25.3 days
- and 25.3 days
Choose the correct spelt name, formula and molecular weight from the following -
- Hydrochloric acid
- Sodium hydroxide
- Potassium permanganate
- Copper sulphate
The principal ionic species of phosphorus in the soil solution between 4.0-8.0 pH is/are -
-
, 
and 
-
and
-
-
and
Which ion is responsible for forming the thinnest diffuse double layer?
Which of the following crop roots has the highest Cation Exchange Capacity (CEC) value?
- Corn
- Wheat
- Tomato
- Beans
Which type of soil erosion is associated with surface crust formation?
- Gully erosion
- Rill erosion
- Sheet erosion
- Splash erosion
The terms ‘light soil’ and ‘heavy soil’ refer to -
- Particle density
- Bulk density
- Ease of tillage
- Soil weight
Which electrode is most commonly used to measure the redox potential (Eh) of soil?
- Glass electrode
- Platinum electrode
- Zinc electrode
- Copper electrode
The ratio of increasing order average chemical composition of Earth’s crust for Al, Ca, K and Fe is -
The silicon ion is equidistant from which four ions in the main constituent of the tetrahedral unit made of silica?
- Phosphorus
- Potassium
- Nitrogen
- Oxygen
As per the Modern System of Soil Classification, which order of soil is NOT found in Rajasthan?
- Entisol
- Inceptisol
- Andisol
- Aridisol
Which radiation monitoring instrument works on the principle of ionisation of gas?
- GM counter
- Mass spectrometer
- Autoradiography plate
- Liquid scintillation counter
Sediments deposited in freshwater lakes are known as -
- Lacustrine
- Aeolian
- Alluvium
- Colluvium
Radioactivity was discovered in 1896 by -
- Ernest Rutherford
- Pierre Curie
- Henri Becquerel
- Marie Curie
For the preparation of a standard pH 4.0 buffer for calibration, which chemical compound is used?
- M Potassium biphthalate
- M Potassium bisulfate
- M Potassium biphosphate
- M Potassium bicarbonate
Phenyl phosphorodiamidate (PPD) is a -
- Nitrification inhibitor
- Urease inhibitor
- Growth promotor
- Slow-release fertiliser
On addition of an electrolyte to the soil colloidal system, the cations of the added electrolyte tend to accumulate on the solution side of the electrical double layer, in the vicinity of which layer?
- Stern Layer
- Debye-Huckel Layer
- Gouy-Chapman Layer
- Helmholtz Layer
Among various accessory minerals, tourmaline has the closed-chain structure, which is also known as
- Phyllosilicates
- Nesosilicates
- Cyclosilicates
- Sorosilicates
The assessment of soil quality can be viewed as a primary indicator of the sustainability of which management?
- Integrated nutrient management
- Land management
- Plant needs-based nutrient management
- Site-specific nutrient management
Generally, which cation requirement is higher in dicots than in monocots?
- Monovalent
- Divalent
- Trivalent
- None of these
The elutriation technique is related to which of the following?
- Determination of soil texture
- Determination of the CEC of soil
- Determination of lime requirement
- Determination of soil structure
The World Health Organisation’s standard for nitrate-N in water is -
-
mg
-
mg
-
mg
-
mg
A falling raindrop produces many important effects during splash erosion. Choose the correct pair out of the listed effects below
- (A), (B) and (E)
- (A), (B) and (C)
- (A), (B), (C) and (E)
- (A), (B), (C) and (D)
A gneissic rock is a laminated or banded metamorphic rock which is similar in mineralogical composition to -
- Conglomerate
- Dolomite
- Granite
- Limestone
Which of the following is a dominant soil-forming process in arid and semi-arid regions of India?
- Podzolization
- Calcification
- Pedoturbation
- Gleization
Match List-I with List-II and select the correct pair for Nutrients and Authors who Discovered Essentiality…
- (a)-(III), (b)-(IV), (c)-(I), (d)-(II)
- (a)-(IV), (b)-(II), (c)-(III), (d)-(I)
- (a)-(II), (b)-(I), (c)-(III), (d)-(IV)
- (a)-(III), (b)-(IV), (c)-(II), (d)-(I)
What is Mucigel?
- Chemical compound release through plant metabolic processes
- Gelatinous layer composed of a mixture of mucilages and soil particles
- Gel released by bacteria
- Complex compounds are produced by roots through bacterial degradation
The concept of ‘L-value’ was proposed by -
- Nicolson (1961)
- Larsen (1967)
- Olsen (1954)
- Fried (1964)
The excavation and destructive action of water is called -
- Denudation
- Hydrolysis
- Hydration
- Oxidation
Which of the following statements is incorrect?
- The lime requirement can be predicted accurately when the soil series is known.
- More lime is required to change the pH if the soil contains less humus.
- Lime reduces excessive uptake of potassium.
- None of these
Which oil cake has having highest nitrogen content?
- Castor cake
- Groundnut cake
- Linseed cake
- Neem cake
The pH of a 0.01M HCl solution is approximately -
The potentiometric titration curves are usually presented in what shape when the titration is mostly carried out with a base?
- Exponential
- Parabolic
- Hyperbolic
- Sigmoidal
Who was the first to advocate classification of soils based on their own properties rather than based on soil-forming factors?
- Dokuchaev
- Jenny
- Marbut
- Milton Whitney
Soils having illite as the dominant clay mineral are mainly associated with the problem of -
- P- fixation
-
fixation
- Swelling and shrinkage
- K- fixation
The main source of negative charges in 2:1 clay minerals is -
- Organic coating
- Adsorbed ions
- Lattice oxygen
- Isomorphous substitution
The first scientist who proposed the concept of factors of soil formation was
- Dokuchaev
- Hilgard
- Guy Smith
- Jenny
The Cation Exchange Capacity (CEC) of acid soils can be determined by which method?
- Neutral normal ammonium acetate method
- Olsen method
- Barium chloride method of Gillman
- Sodium acetate method of Polemio and Rhoades
Cadmium contamination in agricultural soils is most often linked to -
- Organic pesticides
- Phosphate fertilizers
- Gypsum application
- Use of urea
Which microbe is NOT related to the oxidation-reduction of sulphur in soil?
- Thiobacillus
- Gallionella
- Beggiatoa
- Desulphovibrio
Which scale is best suited for soil mapping in micro-watershed planning and field-level interventions?
- :10,000
- :10,00,000
- :250,000
- :50,000
Under submerged soil conditions, the redox potential -
- increases significantly.
- decreases due to oxygen depletion.
- remains unchanged.
- increases due to nitrate build-up.
Anion Exchange Capacity (AEC) is usually highest in soils with -
- High organic matter
- High pH
- Kaolinite-type clay
- Allophanic clay
How much (AR grade, air dried) is required to prepare 1 litre volume of 200 ppm of P solution?
- g
- g
- g
- g
The chemical formula of the gas released in the Bhopal tragedy in 1984 was
Factors affecting the thickness of the diffuse double layer are
- (A), (B) and (D)
- (A), (B) and (C)
-
-
- and (D)
-
-
- and (D)
- and (D)
-
- and (D)
- and (D)
- and (D)
-
-
- and (C)
-
-
- and (C)
- and (C)
-
- and (C)
- and (C)
- and (C)
Out of these soils, which are typical peaty saline soils having accumulation of large quantities of soluble salts and dissolved or free acidic substances?
- Coastal saline soils
- Podsolic soils
- Acid sulphate soils
- Submerged soils
Fibrists and Saprists are suborders of which of the following soil orders?
- Histosols
- Spodosols
- Vertisols
- Andisols
Which clay mineral is formed by recrystallisation during intensive acidic weathering?
- Illite
- Kaolinite
- Chlorite
- Vermiculite
VAM fungi fall under ….group.
- Zygomycota
- Ascomycota
- Ectomycorrhiza
- Endomycorrhiza
The soil information system is based on a database obtained through remote sensing and ground survey in combination with
- LGP and DSS
- GIS and DSS
- SOTER and DSS
- AER and DSS
For the separation of sand, silt and clay particles, the principle followed is -
- Darcy’s law
- Stokes’ law
- Boltzmann equation
- Fick’s law
The growing root tips and roots of young plants often exhibit Cation Exchange Capacity (CEC) values -
- Lowest
- Highest
- Medium
- None
Which soil survey is mainly used to select experimental research sites?
- Detailed reconnaissance survey
- Reconnaissance survey
- Semi-detailed survey
- Detailed survey
What is the value of Avogadro’s number?
Which method is used for estimating exchangeable sodium?
- Flame photometry
- Colourimetry
- Kjeldahl method
- ICP-OES
The element that has created a lot of concern among environmentalists and is also known as ‘Quicksilver’. Which one is among these?
- Mercury
- Selenium
- Cadmium
- Lead
What is the pH at which Azomethine-H forms a stable colored complex compound with during estimation of available B (Hot Water Soluble)?
Chemical preservative added to FYM to decrease nitrogen losses
- Ammonium sulphate
- Ammonium chloride
- Gypsum
- Rock phosphate
Which of the following is a regulatory body for radiation safety in India?
- ICAR
- AERB
- CSIR
- ISRO
Under severe deficiency, a rapid increase in yield with added nutrients can cause a small decrease in nutrient concentration, which is called -
- Steenberg effect
- Transition effect
- Critical effect
- Toxic effect
The Quantity-Intensity relationship is commonly used to study the availability of -
- Zinc
- Iron
- Nitrogen
- Potassium
What is the chemical composition of Devarda’s alloy?
- % Cu, 5% Al, 50% Zn
- % Cu, 45% Zn, 50% Al
- % Cu, 45% Zn, 5% Al
- % Cu, 45% Al, 5% Zn
The conversion of ammonium to nitrite and nitrate in soil is
- A biological process
- A physical process
- A photochemical process
- A chemical process
Extracellular enzymes are essential for the decomposition of which compound, because the microbial cell is impenetrable to these large compounds?
- Monomers
- Polysaccharides
- Monosaccharides
- Glucose
What is the nutrient index, if 10, 20 and 30 soil samples are low, medium and high deficient, respectively?
What are the main ingredients used in the manufacturing of enriched superphosphate (32% )?
- Rock phosphate, Sulfuric acid and Nitric acid
- Rock phosphate, Sulfuric acid and Hydrochloric acid
- Rock phosphate, Sulfuric acid and Phosphoric acid
- Rock phosphate, Sulfuric acid, Hydrochloric acid and Nitric acid
In which radiation detection process, silver halide affected by ionising radiations in photographic emulsions?
- Liquid Scintillation
- Autoradiography
- Solid Scintillation
- Geiger-Muller Counter
Acid sulphate soils are typically found in -
- Coastal areas
- Arid regions
- Semi-arid regions
- Mountainous regions
Which of the following is NOT generally used as a base map in soil survey?
- Aerial Photographs
- Cadastral map
- Soil fertility map
- Topographic map
The ideal range of soil temperature for germination of most seeds is -
Lower …… states of Fe, Mn and Cu are more soluble than higher …… states at the normal pH range of soils.
- Hydroxide
- Reduction
- Oxidation
- Hydrated
Soil crusting is mainly associated with which type of soil?
- Silty clay loam soil
- Loamy soil
- Sandy soil
- Clayey soil
The main method of soil decontamination from industrial waste is -
- Restoration
- Immobilisation of pollutants
- Soil washing
- Phytoremediation
The concept of “Benchmark Soils” was first introduced by the Soil Survey Group of ………
- India
- Australia
- Hawaii
- Russia
The pH of calcareous soil is usually above 7 and may be as high as..
Which of the following is a Chemoheterotrophic bacterium?
- Nitrosomonas
- Frankia
- Azospirillum
- Thiobacillus
Which of the following is NOT a diagnostic surface horizon (epipedon) in Soil Taxonomy?
- Mollic
- Argillic
- Umbric
- Histic
The SI unit of radioactivity, representing one disintegration per second, is -
- Sievert (Sv)
- Becquerel (Bq)
- Curie (Ci)
- Grey (Gy)
In Chepil and Woodruff’s equation of soil loss by wind erosion, , I denotes
- Soil type
- Rainfall intensity
- Soil roughness
- Soil erodibility
The rate of decay of radioactive elements -
- increases with time.
- remains constant throughout the decay.
- decreases as the number of decaying atoms decreases.
- stops after the half-life period.
Overliming of acid soils may induce a deficiency of which nutrient?
- Sulphur
- Molybdenum
- Boron
- Nitrogen
Vermiculite can adsorb and preferentially over , whereas the reverse is true for which clay?
- Kaolinite
- Hallocite
- Illite
- Montmorillonite
The value of Gibbs Free Energy Change () at equilibrium is -
- Zero
- Infinite
- Negative
- Positive