RPSC Rajasthan ARO Agricultural Chemistry 2020 Solved Paper (English) — Agri Master Mind
What is the specific volume of fine textured soil? (RJ ARO Agri. Chemistry 2020)
- 0.50 m³Mg-1
- 0.65 m³Mg-1
- 0.90 m³Mg-1
- 1.10 m³Mg-1
Which minerals are dominant in schist, a metamorphic rock? (RJ ARO Agri. Chemistry 2020)
- Feldspar and Mica
- Mica and Chlorite
- Calcite and Dolomite
- Quartz and Chlorite
Which mineral is an example of tectosilicate? (RJ ARO Agri. Chemistry 2020)
- Pyroxenes
- Tourmaline
- Biotite
- Quartz
In which soil horizon are yellow mottles of jarosite typically found? (RJ ARO Agri. Chemistry 2020)
- Sulphuric Horizon
- Agric Horizon
- Oxie Horizon
- Argillic Horizon
What components make up a Geographical Information System (GIS)? (RJ ARO Agri. Chemistry 2020)
- Hardware
- Software
- Humanware
- All of these
What is the required thickness of a platinum electrode for determining oxygen diffusion rate? (RJ ARO Agri. Chemistry 2020)
- gauge
- gauge
- gauge
- gauge
What type of consistency is ideal for puddling? (RJ ARO Agri. Chemistry 2020)
- Sticky consistency
- Friable consistency
- Viscous consistency
- Plastic consistency
What is the hardness of apatite on the Mohs scale? (RJ ARO Agri. Chemistry 2020)
What is the flocculating power of calcium compared to sodium? (RJ ARO Agri. Chemistry 2020)
- >43
- >63
- >83
What is the diameter of medium-class granular structure? (RJ ARO Agri. Chemistry 2020)
- mm
- mm
- mm
- mm
Match List-I (Elements) with List-II (Functional Roles). List-I: A. S (Sulfur) B. Ca (Calcium) C. Mo (Molybdenum) D. B (Boron) List-II: i. Structural Components ii. Redox Reagent iii. Enzyme Activators iv. Un
- ii ii iv iii
- iv i iii ii
- i iv iii ii
- i iv ii iii
Who discovered the essentiality of iron in plants? (RJ ARO Agri. Chemistry 2020)
- Sachs and Knop
- C. Sprengel
- K. Warington
- E. Gris
Which nutrient enhances the fertility of male flowers? (RJ ARO Agri. Chemistry 2020)
- Fe (Iron)
- Cu (Copper)
- Zn (Zinc)
- Mo (Molybdenum)
What happens to the cation exchange capacity (CEC) of soils when: (RJ ARO Agri. Chemistry 2020)
- Increase the soil pH
- Decrease the soil pH
- Decrease activity of H+
- All
What is the safe limit of water-soluble boron in soil for crop growth? (RJ ARO Agri. Chemistry 2020)
- <0.3 ppm
- <0.5 ppm
- <0.7 ppm
- <0.9 ppm
What is the cation exchange capacity (CEC) of sesquioxides? (RJ ARO Agri. Chemistry 2020)
- meq/100g
- meq/100g
- meq/100g
- meq/100g
What is the total area of salt-affected soils in India? (RJ ARO Agri. Chemistry 2020)
- Mha
- Mha
- Mha
- Mha
Which elements readily form metallic bonds? (RJ ARO Agri. Chemistry 2020)
- Lithophile elements
- Chalcophile elements
- Siderophile elements
- Atmosphile elements
When was the IRS-IC satellite launched? (RJ ARO Agri. Chemistry 2020)
- December, 1995
- August, 1997
- June, 1994
- December, 1998
Soil taxonomic category which is most useful for making land use plans of a small area (RJ ARO Agri. Chemistry 2020)
- Family
- Soil Order
- Series
- Great Group
Which statement is true regarding field capacity? (RJ ARO Agri. Chemistry 2020)
- Field capacity signifies the upper limit of available water.
- Field capacity signifies the lower limit of available water.
- Field capacity signifies the upper limit of capillary water.
- Field capacity signifies the lower limit of capillary water.
Why can the pH of calcareous soil be as high as 8.3? (RJ ARO Agri. Chemistry 2020)
- High partial pressure of CO₂
- Formation of undissociated carbonic acid
- Reduced hydrolysis of CaCO₃
- All of these
Which humic fraction is soluble in water, acid, and alkali? (RJ ARO Agri. Chemistry 2020)
- Fulvic acid
- Humic acid
- Hymatomelanic acid
- Humin
Which statement is true regarding submergence? (RJ ARO Agri. Chemistry 2020)
- Submergence increases the pH of alkali soil.
- Submergence increases the redox potential.
- Submergence increases the specific conductance.
- Submergence decreases the availability of native phosphorus.
What is the critical oxygen diffusion rate below which plant root growth ceases? (RJ ARO Agri. Chemistry 2020)
- × 10⁻⁴ g cm⁻² min⁻¹
- × 10⁻⁴ g cm⁻² min⁻³
- × 10⁻³ g cm⁻² min⁻¹
- × 10⁻⁵ g cm⁻² min⁻¹
What is the surface charge density of smectite clay mineral? (RJ ARO Agri. Chemistry 2020)
- × 10⁻⁶ mol m⁻²
- × 10⁻⁶ mol m⁻²
- × 10⁻⁶ mol m⁻²
- × 10⁻⁶ mol m⁻²
Which clay mineral is dominant in alluvial soils? (RJ ARO Agri. Chemistry 2020)
- Smectite
- Vermiculite
- Kaolinite
- Illite
Which combination is an example of zonal soil? (RJ ARO Agri. Chemistry 2020)
- Sierozem soil
- Desert soil
- Alluvial soil
- Saline soil
Which symbol designates the accumulation of silica? (RJ ARO Agri. Chemistry 2020)
- p
- q
- r
- s
Which soil temperature regime has a mean annual temperature of 15 to <22 °C? (RJ ARO Agri. Chemistry 2020)
- Mesic
- Thermic
- Cryic
- Hyperthermic
Which statement is true regarding soil survey? (RJ ARO Agri. Chemistry 2020)
- Detailed survey is used for village/watershed planning.
- :50,000 base map is used for Reconnaissance survey.
- Semi-detailed survey is used for regional planning.
- Frequency of observation in rapid reconnaissance survey is 2 in 10,000 ha.
What is the distance between field observations in a low-intensity detailed survey? (RJ ARO Agri. Chemistry 2020)
- m
- m
- m
- m
Which Azospirillum species promotes nitrogen fixation in wheat crops? (RJ ARO Agri. Chemistry 2020)
- A. lipoferum
- A. oryzae
- A. brasilense
- A. candenre
How many hydrogen moles are produced during nitrification of 1 mole of NH₄? (RJ ARO Agri. Chemistry 2020)
- mole
- moles
- moles
- moles
Minamata disease is caused due to toxicity of which element? (RJ ARO Agri. Chemistry 2020)
- As
- Cd
- Pb
- Hg
The global warming potential (GWP) of N₂O gas is (RJ ARO Agri. Chemistry 2020)
What process involves the replacement of interlayer potassium in micas by protons or hydronium ions to produce illite? (RJ ARO Agri. Chemistry 2020)
- Oxidation
- Reduction
- Hydration
- Hydrolysis
What is the correct weathering sequence of the following minerals? (RJ ARO Agri. Chemistry 2020)
- Biotite > Potash feldspar > Muscovite > Quartz
- Biotite > Muscovite > Potash feldspar > Quartz
- Quartz > Muscovite > Potash feldspar > Biotite
- Quartz > Biotite > Muscovite > Potash feldspar
At pH above 6, what charge does the soil colloidal complex possess? (RJ ARO Agri. Chemistry 2020)
- Net positive charge
- Net negative charge
- Zero net charge
- None of these
Who divided soil formation factors into "active" and "passive" components? (RJ ARO Agri. Chemistry 2020)
- Jenny, H
- Dokuchaev, V
- Hilgard, E.W.
- Joffe, J.S.
Which genetic system category includes alluvial soils? (RJ ARO Agri. Chemistry 2020)
- Zonal
- Azonal
- Intra-zonal
- Low land
What process involves the removal of iron and aluminum as complexes with humus from the upper part of the soil and its deposition at greater depth? (RJ ARO Agri. Chemistry 2020)
- Laterization
- Clay migration or lessivage
- Podzolization
- Gleization
What term describes an epipedon with a sandy horizon, 100 cm or more thick, over an argillic horizon? (RJ ARO Agri. Chemistry 2020)
- Grossarenic Epipedon
- Folistic Epipedon
- Plaggen Epipedon
- Melanic Epipedon
What are the upper and lower limits of the Soil Moisture Control Section (SMCS) in loamy soils? (RJ ARO Agri. Chemistry 2020)
- and 60 cm
- and 30 cm
- and 90 cm
- and 100 cm
Which soil moisture regime dominantly represents India? (RJ ARO Agri. Chemistry 2020)
- Udic
- Ustic
- Aridic
- Torric
Which soil orders do desert sandy soils of India primarily belong to? (RJ ARO Agri. Chemistry 2020)
- Vertisols and Aridisols
- Ultisols and Aridisols
- Oxisols and Aridisols
- Entisols and Aridisols
How does intense weathering affect the Zero Point of Charge (ZPC) of soil? (RJ ARO Agri. Chemistry 2020)
- Lower pH
- Higher pH
- Neutral pH
- First low pH, then neutral pH
Which color do minerals like Manganese oxide impart to soil? (RJ ARO Agri. Chemistry 2020)
- Brown
- Grey
- Yellow
- Black
What is the result of lower albedo in soil? (RJ ARO Agri. Chemistry 2020)
- High solar energy absorption
- Low solar energy absorption
- High light penetration
- Low light penetration
What is the Chalka soil of Telangana known for? (RJ ARO Agri. Chemistry 2020)
- Productivity
- Hardness
- High organic matter content
- Deepness
Which mineral horizon is characterized by the loss of silicate clay, iron, aluminum, resulting in a concentration of sand and silt particles? (RJ ARO Agri. Chemistry 2020)
- A-Horizon
- B-Horizon
- E-Horizon
- R-Layers
Which statement is correct regarding the diffuse double layer? (RJ ARO Agri. Chemistry 2020)
- Higher electrolyte concentration increases thickness
- Higher valance of counter ion increases thickness
- Increase in dielectric constant of medium increases thickness
- Increase in temperature increases thickness
What do Goldschmidt's Laws explain? (RJ ARO Agri. Chemistry 2020)
- Structural characteristics of Phyllosilicates
- Chemistry of colloidal solution
- Sorption properties of soil colloids
- Electrokinetic phenomenon in soil colloids
What is the order of preference for anions in anion exchange? (RJ ARO Agri. Chemistry 2020)
- SiO4^2- > PO4^3- > SO4^2- > NO3^-
- NO3^- > SO4^2- > PO4^3- > SiO4^2-
- SiO4^2- > SO4^2- > PO4^3- > NO3^-
- NO3^- > SiO4^2- > PO4^3- > SO4^2-
What primarily influences the lime potential of a soil? (RJ ARO Agri. Chemistry 2020)
- Soil-water ratio
- Salt content
- Electrolyte concentration
- None of these
How does increasing salt concentration affect the pH value of an alkaline soil? (RJ ARO Agri. Chemistry 2020)
- Decreased
- Increased
- First decreased then increased
- No change
Which of the following is not referred to as agricultural lime? (RJ ARO Agri. Chemistry 2020)
- CaCO3 (Calcium Carbonate)
- MgCO3 (Magnesium Carbonate)
- CaO (Calcium Oxide)
- CaCl2 (Calcium Chloride)
Which organic fraction is insoluble in both acid and alkali? (RJ ARO Agri. Chemistry 2020)
- Humic
- Humin
- Fulvic
- All of these
What is the typical redox potential range for oxidized soils? (RJ ARO Agri. Chemistry 2020)
- +400 to +700 mV
- +200 to +250 mV
- +100 to +400 mV
- -100 to -300 mV
What is the typical pF value at field capacity? (RJ ARO Agri. Chemistry 2020)
Which mineral is a primary source of Mg? (RJ ARO Agri. Chemistry 2020)
- Magnetite
- Dolomite
- Micas
- Orthoclase
Who developed the Ammonium Acetate method for K determination? (RJ ARO Agri. Chemistry 2020)
- Keeney and Bremner
- Williams and Steinberg
- Hanway and Heidel
- Bray and Kurtz
What is the typical K2O content range in illite? (RJ ARO Agri. Chemistry 2020)
- %
- %
- %
- %
Which factor does not increase available P after soil submergence? (RJ ARO Agri. Chemistry 2020)
- Hydrolysis of Fe and Al phosphate
- Dissolution of occluded P
- Increased mineralization of organic P in acid soil
- Decreased diffusion of P
Which of the following shows endotrophic mycorrhiza? (RJ ARO Agri. Chemistry 2020)
- Boletus
- Glomus
- Amanita
- Rhizoctonia
What is the optimum temperature range for psychrophilic bacteria? (RJ ARO Agri. Chemistry 2020)
- Less than 5 °C
- Less than 20 °C
- Less than 35°C
- Less than 45 °C
Where do plants primarily obtain the elements constituting the majority of their dry weight? (RJ ARO Agri. Chemistry 2020)
- Soil
- Water
- Decomposition of organic matter
- Air
What was the first fertilizer manufactured in India? (RJ ARO Agri. Chemistry 2020)
- DAP (Diammonium Phosphate)
- DSP (Dicalcium Phosphate)
- SSP (Single Super Phosphate)
- Urea
What elements are added to soil through Rock Phosphate application? (RJ ARO Agri. Chemistry 2020)
- Nickel and Chromium
- Mercury and Selenium
- Cadmium and Lead
- Arsenic and Nickel
What is considered the main factor contributing to water pollution? (RJ ARO Agri. Chemistry 2020)
- Pesticides
- Herbicides
- Detergent
- Industrial waste
What term describes the downward movement of water through soil? (RJ ARO Agri. Chemistry 2020)
- Leaching
- Percolation
- Infiltration
- Run-off
Which greenhouse gas is released from paddy fields? (RJ ARO Agri. Chemistry 2020)
- Carbon dioxide
- Carbon monoxide
- Methane
- Nitric oxide
What is reduced in water due to eutrophication? (RJ ARO Agri. Chemistry 2020)
- Dissolved carbon dioxide
- Dissolved salts
- Dissolved nitrate
- Dissolved oxygen
What pollutants cause acid rain? (RJ ARO Agri. Chemistry 2020)
- SO₂ and NO₂
- SO₂ and CO
- SO₂ and NH₃
- NH₃ and CO
What is the specific heat of apatite mineral? (RJ ARO Agri. Chemistry 2020)
- cal/g°C
- cal/g°C
- cal/g°C
- cal/g°C
Which element's toxicity caused Itai-Itai disease in Japan? (RJ ARO Agri. Chemistry 2020)
- Nickel
- Cadmium
- Lead
- Mercury
In which Indian state are cat clays primarily found? (RJ ARO Agri. Chemistry 2020)
- Kerala
- Karnataka
- Tamil Nadu
- Assam
What is the sequence of color variables in the Munsell soil color chart? (RJ ARO Agri. Chemistry 2020)
- Chroma, Value, Hue
- Chroma, Hue, Value
- Value, Hue, Chroma
- Hue, Value, Chroma
What organism is responsible for nitrogen-fixing nodules on non-leguminous trees? (RJ ARO Agri. Chemistry 2020)
- Frankia
- Rhizobium
- Azotobactor
- Thiobacillus
Which nutrient's deficiency causes browning in cauliflower? (RJ ARO Agri. Chemistry 2020)
- Mo (Molybdenum)
- B (Boron)
- Cu (Copper)
- Zn (Zinc)
How is potassium sulfate fertilizer manufactured? (RJ ARO Agri. Chemistry 2020)
- Reaction of sylvite with concentrated H₂SO₄
- Reaction of langbeinite with concentrated solution of KCl
- Reaction of KCl with concentrated H₂SO₄
- Reaction of KCl with Na₂SO₄ solution
What is the latent heat of vaporization of water at its boiling point? (RJ ARO Agri. Chemistry 2020)
- cal/gm
- cal/gm
- cal/gm
- cal/gm
Who pioneered field plot experiments in agriculture? (RJ ARO Agri. Chemistry 2020)
- J.W. Leather
- J.B. Boussigault
- L.V. Liebig
- D. Hillel
What is the critical relative humidity (CRH) of wheat? (RJ ARO Agri. Chemistry 2020)
- %
- %
- %
- %
What percentage of nitrogen is available to crops after first-time FYM (Farm Yard Manure) application? (RJ ARO Agri. Chemistry 2020)
- %
- %
- %
- %
Which method determines phosphorus in alkaline soils? (RJ ARO Agri. Chemistry 2020)
- Bray and Kurtz
- Olsen et al
- Mehlich No. 1
- AB-DIPA
Which reagent determines available molybdenum in soil samples? (RJ ARO Agri. Chemistry 2020)
- Morgan-Wolf reagent
- Grigg or Tamn
- DTAP reagent
- AB-DTPA reagent
What color is produced when copper salts are heated in a flame? (RJ ARO Agri. Chemistry 2020)
- Yellow
- Orange
- Green
- Red
What does soil consistency indicate? (RJ ARO Agri. Chemistry 2020)
- Friability
- Plasticity & Stickiness
- Cohesion and Adhesion
- All
Which micro-organism is a phosphate solubilizer? (RJ ARO Agri. Chemistry 2020)
- VAM (Vesicular-Arbuscular Mycorrhiza)
- Glomus
- Gigaspora
- Bacillus
Which soil enzyme indicates oxidative metabolism? (RJ ARO Agri. Chemistry 2020)
- Cellulase
- Amylase
- Urease
- Dehydrogenases
What is the safe limit of chloride ions in irrigation water? (RJ ARO Agri. Chemistry 2020)
- <2 ppm
- <4 ppm
- <6 ppm
- <8 ppm
Which mineral is readily dissolved in water? (RJ ARO Agri. Chemistry 2020)
- Halite (Rock Salt)
- Lime (Calcium Carbonate)
- Quartz (Silicon Dioxide)
- Albite (Sodium Aluminum Silicate)
Where are glacial hills commonly found? (RJ ARO Agri. Chemistry 2020)
- Lacustrine (Lake) deposits
- Alluvial (Water) deposits
- Moraines (Glacial) deposits
- Colluvial (Gravity) deposits
What is the term for a silicate clay-enriched horizon formed by illuviation? (RJ ARO Agri. Chemistry 2020)
- Argillic Horizon
- Nitric Horizon
- Spodic Horizon
- Agric Horizon
In which type of soil is titaniferous magnetite mineral commonly found? (RJ ARO Agri. Chemistry 2020)
- Red soils
- Black soils
- Desert soils
- Laterite soils
What type of survey typically uses maps on the scale of 1:50,000? (RJ ARO Agri. Chemistry 2020)
- Rapid Reconnaissance
- Detailed
- Reconnaissance
- Semi-Detailed
What is the specific surface area of Kaolinite clay minerals? (RJ ARO Agri. Chemistry 2020)
- (m²/g)
- (m²/g)
- (m²/g)
- (mg)
Which law uses the equation qgi-D? (RJ ARO Agri. Chemistry 2020)
- Darcy's Law (fluid flow through porous medium)
- Fick's Law (diffusion)
- Poiseuille's Law (fluid flow through pipes)
- Stock's Law (terminal velocity of particles)
What type of erosion occurs when a falling raindrop generates a force equal to almost 14 times its weight? (RJ ARO Agri. Chemistry 2020)
- Sheet Erosion
- Splash Erosion
- Rill Erosion
- Gully Erosion
What mineral has the chemical formula CaAl₂Si₂O₈? (RJ ARO Agri. Chemistry 2020)
- Albite (sodium-rich feldspar)
- Diopside (pyroxene mineral)
- Anorthite (calcium-rich feldspar)
- Calcite (carbonate mineral)
Which symbol represents the soil erodibility factor in the Universal Soil Loss Equation (USLE)? (RJ ARO Agri. Chemistry 2020)
- R (Rainfall erosivity factor)
- K (Soil erodibility factor)
- L (Slope length factor)
- S (Slope steepness factor)
What is the cation exchange capacity (CEC) of vermiculite? (RJ ARO Agri. Chemistry 2020)
- mol (P+)/kg soil
- mol (P+)/kg soil
- mol (P+)/kg soil
- mol (P+)/kg soil
What type of clay mineral is halloysite? (RJ ARO Agri. Chemistry 2020)
- :1 type clay mineral
- :1 type clay mineral
- :1:1 type clay mineral
- :2 type clay mineral
What percentage of iron is found in the Earth's crust composition? (RJ ARO Agri. Chemistry 2020)
- %
- %
- %
- %
What is the Zero Point of Charge (ZPC) of silicic acid? (RJ ARO Agri. Chemistry 2020)
What type of soil forms in regions where time has been a limiting factor? (RJ ARO Agri. Chemistry 2020)
- Zonal soils
- Intra-Zonal soils
- Azonal soils
- Zonal and Intra-Zonal soil
What type of acidity is caused by hydrogen and aluminum ions in the soil solution? (RJ ARO Agri. Chemistry 2020)
- Passive Acidity
- Reserve Acidity
- Active Acidity
- Exchangeable Acidity
What is the permissible limit of boron in irrigation water? (RJ ARO Agri. Chemistry 2020)
- mg L⁻¹
- 5 mg L⁻¹
- 3.0 mg L⁻¹
- mg L⁻¹
Who discovered the essentiality of nickel (Ni) for plant growth? (RJ ARO Agri. Chemistry 2020)
- P.H. Brown
- E. Gris
- I.S. McHargue
- C. Sprengel
What element's deficiency causes interveinal chlorosis and a streaked or patchy effect on older leaves? (RJ ARO Agri. Chemistry 2020)
- Magnesium
- Nitrogen
- Calcium
- Chloride
What is the chemical formula of Chile saltpeter? (RJ ARO Agri. Chemistry 2020)
- NaNO₃
- NaCl
- NaSO₄
- NaHCO₃
In which type of dominant clay mineral is potassium fixation found? (RJ ARO Agri. Chemistry 2020)
- Kaolinite
- Vermiculite
- Chlorite
- Montmorillonite
What is the K₂O content in MOP (Muriate of Potash) fertilizer? (RJ ARO Agri. Chemistry 2020)
- %
- %
- %
- %
What is the typical CEC of sand soils (light colored)? (RJ ARO Agri. Chemistry 2020)
- meq/100g
- meq/100g
- meq/100g
- meq/100g
What is the zinc content in zinc sulphate monohydrate fertilizer? (RJ ARO Agri. Chemistry 2020)
- %
- %
- %
- %
Which element is crucial for pollen tube growth and seed development? (RJ ARO Agri. Chemistry 2020)
- Mg (Magnesium)
- B (Boron)
- Mo (Molybdenum)
- Ni (Nickel)
What term describes elements with the same atomic number but different atomic mass? (RJ ARO Agri. Chemistry 2020)
- Isobar
- Isotopes
- Isotons
- None of these
Who first reported the Law of Mass Action? (RJ ARO Agri. Chemistry 2020)
- Thomson
- Davies
- Garrels and Christ
- Guldberg and Waage
What term describes the negative charge on clay surface and swarm of positive counterions? (RJ ARO Agri. Chemistry 2020)
- Helmholtz Double Layer
- Gouy-Chapman Double Layer
- Electric Double Layer
- None of these