Soil Science — Agri Master Mind
Example of igneous rock
- Diorite
- Gabbro
- Peridotite
- All of these
Sedimentary rocks are …
- Limestone
- Andesite
- Basalt
- None
Which is incorrect regarding formation
- Slate from sandstone
- Gneiss from granite
- Quaetz from quartz
- None
Potash dominate minerals
- Micas
- Feldspare
- Quartz
- Olivine
Boro – alumino silicate
- Olivine
- Tourmaline
- Quartz
- All of these
Source of Mg
- Brucite
- Carbamate
- Muscovite
- None
Most resistance mineral to weathering
- Augite
- Muscovite
- Biotite
- All of these
Acids rocks are
- 65 – 70 % silica
- 40 -55 % silica
- 55 – 65 % silica
- None
Chemical weathering involve
- Disappearance of certain mineral
- Formation of secondary mineral
- Both
- None
Kankar found in
- Red soils
- Black cotton soils
- Both
- None
1
Iron pyrite formation through
- Oxidation
- Reduction
- Hydration
- Hydrolysis
Highest element in earth crust
- Al
- Fe
- Si
- Oxygen
Active factors are
- Climate
- Parent material
- Topography
- Time
Washing out is
- Horizonation
- Illuviation
- Eluviation
- Humification
Removal of sesquioxides called
- Podozolization
- Laterization
- Pedoturbation
- Salination
Zonal soil forming process is
- Pedoturbation
- Salination
- Podozolization
- None
Soil includes
- A horizon
- A +B horizon
- A , B, C horizon
- All of these
The soil horizon where maximum biological activity occurs are
- O 1
- O 2
- A
- B
Father of soil science
- V .VDokuchaev
- Kellogg
- Baldwin
- Marbutt
Pedology is derived from …..
- Greek word
- Latin word
- French word
- None
Loose earth material above solid rock is
- Soil
- Solum
- Regolith
- Regosol
Organic soil must contain about
- 20 % OM
- >20 % OM
- <20 % OM
- NONE
Portion of mineral soil volume basis
- 45 %
- 5 %
- 25 %
- 20 – 30 %
Which is not components of soil…
- Air
- Water
- Organic matter
- Light
Law of Minimum is given by
- Von liebig
- Bray
- Stout
- None
Relative proportion of sand and silt and clay
- Soil texture
- Soil structre
- Soil compaction
- None
Size of clay particle
- >0.002mm
- 0.02 -0.002 mm
- 0.02-0.2 mm
- < 2mm
Clay soil called …
- < 40 % clay
- >40 %
- 40 %
- None
Individual aggregates are
- Peds
- Clod
- Both
- None
The arrangement of primary particle are
- Soil texture
- Soil structure
- Soil compaction
- None
Peds are arranged in relatively thin horizontal layers ….
- Platy like
- Prism like
- Block like
- None
Prism like most commonly found in ……
- A horizons
- B horizons
- Both
- None
Shapes of soil structure good for agriculture …..
- Platy like
- Prism like
- Blocky like
- Spheroidal
How much classes of soil structure …
- 5
- 4
- 3
- 2
Soil grades refer to ….
- Degree of aggregation
- Arrangement of primary soi particle
- Proportion of soil particle
- None
Particle density of mineral soil …
- 2. 60 g/cm3
- 1.3g/cm 3
- 1.1 g /cm3
- None
Soil volume is …
- Vs +Vp
- Ws+Wp
- Both
- None
% Pore space
- 100- (BD/PDX100)
- 100- (PD/BDX100)
- BP/PD X100
- NONE
Soil temperature for root development
- 10 -27 C
- 15-45 C
- 20 C
- None
Silicate colloids particle carrying negative charge ….
- Micelles
- Micro pores
- Macro pores
- None
Water molecule are carried by adsorbed cation …
- Holmontz layer
- Stern layer
- Gunny layer
- Ionic layer
Cation dominate in humid region
- Ca2+
- Al 3+
- H +
- All of these
Order of strength of adsorption to focculate soil collids
- Al 3+>H+>Ca2+>Mg2+ > K+>Na+
- Al 3+>H+>Ca2+> Na+>Mg2+ > K+
- Na+> Al 3+>H+>Ca2+>Mg2+ > K+
- None
Range of molar ratio in laterite soil
- 3-4.3
- >2.5
- 2 -2.5
- <1.33
Formula of goethite
- Fe2O3.H2O
- FeOOH
- Both
- None
Allophane is
- Amorphous
- Developed from volcanic ash
- Adsorb cation
- All of these
Tetra hedral is
- Silicate dominate sheet
- Al – dominate sheet
- Mg – dominate sheet
- None
1:1 type clay mineral is
- Kaolinite
- Halloysite
- Nacrite
- All of these
Expanding minerals are
- Vermiculite
- Smectite
- Saponite
- All of these
CEC of montroillonite is
- 80 -150
- 3- 10
- 10 -40
- 100 – 150
Non expanding minerals are
- Illite
- Chlorite
- Both
- None
Ferro- magnesium silicates are
- Chlorite
- Illite
- Vermiculite
- Kaolinite
Total soil order
- 2
- 10
- 11
- 9
Embryonic soil with few diagnisticsfeature , found in humid region
- Spodosol
- Inceptisols
- Entisols
- Histosols
Soil order have shrinkage and swelling property
- Vertisols
- Aridisols
- Ultisols
- Mollisols
Cat clay contain …
- Sulphur
- Calcium
- Silicate
- Boron
Most abundate soil in india
- Black soil
- Alluvial soil
- Red soil
- Laterite soil
Newar alluvium soil called
- Khadar
- Bhangra
- Both
- None
Black soil are derived from
- Granite
- Quartz
- Limestone
- None
Clay group dominate in black soil …
- Montmorillonite
- Beidelitic
- Both
- None
Red colour of soil due to
- Postash
- Humus
- P2O5
- Fe
Weight of 1 furrow slice
- 2x10^6 kg/ha
- 3x10^6 kg /ha
- 4x10^6kg/ha
- None
Nitrogen content in humus
- 50%
- 35 %
- 5%
- 3 %
Medium molecular weight and alkali soluble but acid insoluble
- Fulvic acid
- Humin
- Humic acid
- None
Which is most susceptible to microbal attack
- Fulvic acid
- Humin
- Humic acid
- All of these
C:N ratio of humus
- 9:1
- 10:1
- 15:1
- None
Humus have
- Low plasticity and cohesion
- Negative charge
- High pH
- All of these
Value of Bemlen factor
- 1.724
- 1.64
- 1.54
- 1.44
Muck soils are
- Low decomposed
- Highly decomposed
- Both
- None
C: N ratio >20 takes place
- Immobilization
- Both immobilization and mineralization
- Mineralization
- None
Range for high nitrogen
- 250 kg /ha
- 250 -500 kg /ha
- >500 kg/ ha
- None
Mineralization process occur through
- Aminization
- Ammonification
- Nitrification
- None
Voltalization is losses of
- NH3
- NO3
- NO2
Nitrification occurs through
- Nitrosomonas
- Nitrobacter
- Both
- None