Soil Science Flashcards
1
Q
Father of soil science?
A
Vasily Dakuchaiev
2
Q
A natural body composed of minerals and organic content having a definite genesis and a distinct nature of its own is?
A
Soil
3
Q
A pedon is?
A
The smallest unit or volume of soil
4
Q
The study of soils in relation to crop growth, nutrition and yield is called as?
A
Edaphology
5
Q
A study of soils, it’s classification, pedogenesis and morphology is?
A
Pedology
6
Q
Different types of weathering of rocks?
A
Physical, Chemical, Biological
7
Q
Physical and chemical weathering occurs due to?
A
Physical - disintegration
Chemical - decomposition
8
Q
Biological weathering occurs due to?
A
Disintegration + Decomposition
9
Q
Ultimate result of soil formation is?
A
Profile development
10
Q
Rocks formed from the consolidation of sediments accumulated due to wind and water action on Earth is?
A
Sedimentary rock’s
11
Q
Limestone, sandstone, shale, peat and Fuller’s earth are examples of?
A
Sedimentary rocks
12
Q
Sedimentary rocks composed of coarse grained, sand like particles are ?
A
Arenaceous
Eg: sandstone breccia
13
Q
Sedimentary rocks composed of clay-sized particles?
A
Argillaceous
Eg: Mudstone, shale, Fuller’s earth
14
Q
Sedimentary Rocks composed of carbonate of lime, magnesia and bases?
A
Calcareous.
Eg: limestone, challk
15
Q
Sedimentary rocks composed of decomposing vegetation under anaerobic processes?
A
Carbonaceous
Eg: peat, coal
16
Q
Sedimentary rocks composed of minute plants and animals like diatoms?
A
Silicious rocks
(Rocks from ciliated animals)
17
Q
The strongly deformed type of rock, short of metamorphic conditions?
A
Anthracite (from bituminous)
18
Q
Primary rocks or massive rocks are?
A
Igneous rocks
19
Q
Granite, Diorite and Gabbro are examples of what kind of rocks?
A
Intrusive (plutonic) igneous rocks
20
Q
Basalt, Pumice, Obsidian are examples of what kind of rocks?
A
Igneous extrusive
21
Q
Igneous rocks with more than 65% silica content is called as?
A
Acidic rocks
Eg: Granite, pegmatite, rholite
22
Q
Igneous rocks with 55-65% silica are called?
A
Intermediate
Eg: Andesite, Diorite, Syenite
23
Q
What is the range for sub-acidic and sub-basic igneous rocks?
A
Sub-acidic: 60-65 -> Diorite
Sub basic: 56-60 -> Syenite
24
Q
Igneous rocks with 40-55% silica ?
A
Basic
Eg: Basalt, Gabbro, dolerite
25
Granite classifications are? *(Acidic, basic, intrusive, extrusive, etc)*
G=Ai -> acidic, intrusive
26
Basalt rock classification
B=Be -> basic, extrusive
Popular in deccan lands
27
Diorite classification
D=ii -> intermediate, intrusive
28
Rocks formed due to the solidification of molten magma
Primary Rocks/ Igneous rocks
29
Rocks formed due to heat, pressure, chemically active liquids, has or a combination of them, on previously formed rocks is?
Metamorphic rocks
30
Quartzite and marble is formed from?
Q= Sandstone
M= limestone
31
Poorly sorted material near the base of strong slopes transported by the action of **gravity**?
Colluvium
32
Material that is transported and **deposited by water**, found along major **streams courses** at the bottom of slopes of mountains and along small streams flowing out of drainage basins
Alluvium
33
Materials that have settled due to the quiet water of **lakes**?
Lacustrine
34
Materials picked up, mixed, disintegrated and transported through action of **Glacial ice** - primary due to melting of glaciers
Moraine
35
Wind blown material of silty texture
Loess
36
Wind blown material of sandy texture
Aeolian
37
Soils that bear the name of their parent material
Eolian
38
A process of mixing of soils causing differentiation due to humification, eluviation and illuviation
Pedoturbation
Eg: black soil
39
Processes by which the soil materials are differentiated into several horizons in a profile?
Soil Horizonation
40
Illuviation of Na+ ions
Solonisation
Or Alkalisation
41
Eluviation of Na+ ions
Increasing Mg or Ca conc
Solodisation or Dealkalization
42
Specific Eluviation of salts
Desalinisation
Due to improved drainage in soil
43
Specific illuviation of salts (sulphates, chlorides, magnesium, sodium, potassium)
Salinization
Common in arid and semi arid regions with impeded drainage
44
Illuviation of Ca
Accumulation CaCO3
Calcification
45
A process of soil formation resulting in the development of glei - a bluish grey horizon with mottling of yellow or reddish-brown colours
Gleization
46
Specific illuviation of Silica
Iron and alumina stay in upper layers (Sesquioxides)
Soluble substances are depleted
Laterisation
47
Specific Eluviation of Sesquioxides and humus
Podsolisation
48
% of clay in clayey soil?
35-40%
49
Soils formed under the **supreme influence of parent material** which show advanced development and excessive leaching
Endodynamomorphic soils
*(Endo = still inside parents house)*
50
Soils formed under the predominant influence of **climate**, where effects of **parent materials are obliterated**
Ectodynamomorphic
E**c**to..= climate
51
Organic matter in O horizon?
About 30%
52
Soil forming processes are of 2 types...?
Active - CVO
Passive - PRT
53
Passive soil forming processes include?
* Parent Material
* Relief
* Topography
PRT
54
Active soil forming processes?
CVO
Climate Vegetation Organism
55
The process of soil formation is known as
Pedogenesis
- Fundamental: HEI
- Specific
56
A **complex process** where first simple compounds like sugars and starches are attacked, followed by proteins and cellulose and finally **resistant compounds like tannins** are decomposed forming a **dark coloured** substance
Humification
- A fundamental soil forming process
- Decomposition of OM to Humus
57
Soil with abundant montmorillonite clay, and is the 2nd largest soil group in india, aka a self ploughing soil
Black soil
58
Which soil has high clay content, Iron, Lime , Calcium and Potassium but is deficient in Nitrogen, Phosphorus, and OM
Black soil
59
Why is black soil best for cotton?
Best water retention capacity and high calcium and potassium in soil
60
Expansive nature of black soil is due to
High presence of montmorillonite clay
61
Area covered by Alluvial soil
43% of land -> 143 km2
Largest soil group in India
62
Which soil is rich in potash, lime & phosphoric acid?
Alluvial
63
Which soil is formed due to leaching effect and is rich in iron and aluminium
Laterite Soil
64
Major secondary minerals in soils
Kaoline, Smectite, Vermiculite, Illite. All 1:1 and 2:1 structured clays
65
Amongst sandy, silty, clayey and loamy soil, which has highest pore space?
Clayey
66
Amongst Sandy, silty, clayey and loamy, which has the highest permeability?
Sandy
67
Diameter of macro-pores
0.06mm
Common in sandy soils
68
What is the diameter of micro capillary pores?
<0.06 mm
More in clayey soils
69
Which soil formation stage has unweathered parent material?
Initial Stage
70
In which soil formation stage has weathering just started but much of the original material is still there?
Juvenile Stage
71
In which soil formation stage is easily weatherable material completely decomposed and not seen, while clay content starts to increase
Virile Stage
72
In which soil formation stage only the most resistant minerals like quartz survive
Senile Stage
73
In which soil formation stage is soil development completed under prevailing conditions?
Final Stage
74
1. It is the relative **Proportion** of sand, silt and clay particles.
2. The **basic property** of soil
3. It cannot be changed unless considerable mechanical and financial inputs are used
Soil **T**exture
(**T** = **P**)
75
1. It is the **Arrangement** of primary & secondary particles in a soil mass
2. It is the study of pore space and their interaction
Soil **S**tructure
(**S** = **A**)
76
Soil Structure is dependent on?
**TCG**
Type (shape)
Class (size)
Grade (strength/weakness)
77
Which is the best type of soil structure for agricultural purposes?
Spheroidal/Crumbly
78
Which type of soil structure is mostly seen in forest top soil or in virgin soil?
Platy Soil
(Mostly Horizontal Development)
79
Which type of **soil structure** is mostly seen in arid or semi-arid sub-soils?
Prism Soil
(Mostly Vertical Development)
80
Primary soil material like sand, silt and clay, when grouped together are called?
Soil Aggregates
81
**Natually formed** soil aggregates are called?
Peds
82
**Artificially** formed soil aggregates are called?
Clods
83
As per International Society of Soil Science (ISSS), what is the particle density of Clay, silt and sandy soil?
Clay: 0-0.002mm
silt: 0.002-0.02mm
sand: 0.02-0.2mm
84
Which is the best kind of soil for agri?
1. Sandy
2. Loam
3. Silt Loam
4. Clayey
5. OM
Silt Loam
85
Soil with what Bulk Density is best for agriculture?
1.3 g/cc
(Silt Loam)
86
How many soil textural classes are there, as per the USDA?
12
87
Will sandy soil have lower bulk density or clayey soil?
Clayey soil
Because of higher organic matter content
88
% of clay and % of OM in the best agricultural soils?
10-20% clay
5-10% OM
*More clay than OM*
89
This kind of soil is:
1. Low in nitrogen
2. Adequate Potash, Phosphoric acid and alkalis present
3. Iron oxide and lime vary within a wide range
Alluvial soil
90
This kind of soil:
1. Varies from loamy to sandy-loam in drier regions and clayey loam towards the delta
2. They have immature and weak profiles
3. They are common in Dooars, Chos and Terai
Alluvial Soil
91
This type of soil is formed due to leaching, high temp & heavy rainfall
It is best for growing of tea, coffee
It is Rich in Iron and aluminium
Laterite
92
How many essential elements are there, necessary for plant growth and of what types?
17
divided into 3 types:
1. Micro (7+1)
2. Macro (6): N,P,K (Pri); Ca, Mg, S (Sec)
3. Non-mineral (3): CHO
93
Nutrient that is: **Imp part of Chlorophyll**. Helps in absorption of phosphorus, nitrogen and sulphur by plants, ripen fruit, reinforce cell wall
Magnesium
94
Basic component of proteins and chlorophyll. Essential role in plant growth, **feeds microorganisms** in soil
Nitrogen
95
Important for **overall structure and cell wall** of the plant - holds it together. Promotes development of root system
Calcium
96
Moves through plant, promotes **movement of sugars**, tugor and stem rigidity, hardening of woody plants, formation of flowering buds. Also increases the plant's overall resistance to cold, diseases, insects, pests, etc. Regulates **stomatal movement**
Potassium
97
A component of several proteins, enzymes and vitamins. Imp role in **oil formation in oil crops** (Soyabean)
Sulphur
98
Overall plant health and tissue growth - formation of fruit, absorption of water and **translocation of sugar**
Boron
*(movement of sugar is K but in options always go for Boron)*
99
Synthesis of proteins, enzymes and **growth hormone**
Zinc
100
Plays an important role in root growth and establishment of young flowering plants and fruits, ripening, photosynthesis. Increased activity of Rhizobium, cell division, **energy storage** and transfer.
Phosphorus
101
Acc to ICRIER, every rupee invested on agriculture will yield?
Rs. 11
