Soil resources Flashcards
topmost layer of Earth’s land surface
Soil
from what are soils derived and by what process?
- from parent rock material
2. process of wear and tear
Decomposed vegetal and animal remains
Humus
Constituents of soil
humus, Silica.clay and sand
strength of soil to support plant life
Soil fertility
____ improves soil structure and fertility
Organic matter
Residual/sedimentary soil is also known as __________
In situ soil
what is in situ soil and example….
- formed in original position by breakup of parent rocks
2. Red soil,desert soil,black soil
transported soil is also called
ex situ soil
What is ex situ soil and example…
- soil transported by various agents
- no well defined profile
- alluvial soil
How are alluvial soils formed?
by the sediments brought down by rivers
what do the rivers deposit in the plains during their journey
alluvium
alluvial soil is also known as _________.
it is known so because…..
Riverine soil as it is mainly found in river basins
alluvial soils occupy ___ of the land area
40%
entire Northern plains consist of ____ soil
Alluvial
Three river systems which deposit alluvial soil ______
indus, ganga, brahmaputra
two types of alluvial soil
bhangar and khadar
_____ is older alluvium and composed of ______ called _______
Bhangar ,lime nodules, kankar
bhangar has a ______ composition
clayey
_______ is newer alluvium
Khadar
why is alluvial soil the most important in India
It contributes the largest share to agricultural wealth of India
Coastal alluvium is of _____ origin
Tidal
In the upper reaches of river valley…. soil is __________ and the particles are ____
coarse,large , non uniform
in the lower parts of the river valley…. soil is ____ and ____
small and uniform
How is alluvial soil …
light and porous
easily tillable
alluvial soil is rich in what minerals
potash, lime
alluvial soil is deficient in _______
nitrogen and humus
what crops can be grown in alluvial soil ( RSTW and 2 other )
Rice
Sugarcane
Tobacco
Wheat
Gram and oil seeds
What are some names for black soil?
Regur soil
Black cotton soil
Lava soil
How is black soil formed
denudation of volcanic rocks
Distribution of alluvial soil
Northern plains
coastal strips of India
plains of Gujarat
( sideways V and gujarat) - map
Distribution of black soil - (the two states where palam has resided and the P’s )
Deccan lava tract
- AP UP MP TN
- maharashtra karnataka
middle of India ( for map)
nature of black soil
fine textured and clayey
black soil is rich in ____
Lime, iron, magnesium
black soil is poor in ______
P,N and Humus
soil which has self aeration capacity and moisture stores in subsoil
black soil
crops grown in blacks soil
COTTON
cereals
oilseeds
citrus fruits ( orange/sweet lime/lemon)
Main feature of black soil
highly moisture retentive
expands when wet and shrinks when dry
moisture retentiveness makes black soil suitable for
dry farming
how is red soil formed
prolonged weathering of old crystalline rocks
how does red soil differ from place to place
basis of parent rock material and climatic conditions
why is red soil red in color?
contains large amounts of ferric oxides
second largest soil group in India
Red soil
distribution of red soil
plateau region of India and some parts of the branch wing of NE India like Nagaland
encircles the entire black soil region
is red soil porous or not?
yes it is porous, loose and aerated
Which soil is not fertile but responds to fertilisers?
Red soil
red soil is poor in ____
N,P,K organic matter
Red soil looks ____ when it is hydrated form
Yellow
why is red soil ideal for dry farming
formed in poor rainfall areas
crops which can be grown in red soil
Vegetables, rice, ragi, tobacco
groundnuts and potatoes also
how is laterite soil formed?
leaching due to tropical rains
What is leaching?
process in which nutrients get percolated down below the soil due to heavy rain
leaching is also known as ___
desilication
two types of laterites
Low land laterites and upland laterites
what is upland and lowland laterites
upland laterite - formed over hills and uplands - residual
lowland laterite - transported upland laterite
what compounds are not washed away during leaching
aluminium compounds
distribution of laterite soil
highland areas of the Peninsular plateau
- Sahyadris
-eastern Ghats
Rajmahal hills
nature of laterite soil
- coarse texture
- soft
- friable
- porous
laterite soil color
red due to ferric oxides
Laterite soil is poor in ___, ____ and ______
lime,magnesium and nitrogen
does laterite soil retain moisture?
no and so it is not fertile
what crops does laterite soil suit?
tapioca, cashewnut, tea, coffee
what is laterite soil normally used for
building purposes
is laterite soil basic/acidic and why?
acidic as alkalis are leached
what is soil erosion?
removal of topsoil cover by water, wind and human activities
types of soil erosion by water
sheet erosion rill erosion gully erosion stream bank erosion sea/shore erosion leaching
name a place where gully erosion can be seen? ( not our streets)
Chambal Valley region
soil erosion causes due to human action
- overgrazing
- loss of vegetation cover
- shifting cultivation
how do soil particles sized > 0.5 mm move and what is it called?
rolling- soil creep
how do soil particles sized 0.1 - 0.5 mm move and what is it called?
bouncing- saltation
how do soil particles sized < 0.1 mm move and what is it called?
detach in wind - suspension
where is overgrazing most prevalent in India?
Rajasthan
Percentage of forest cover in India
21.54 % of total area
farmers plant trees in several rows to check wind erosion.. this is called as_____
wind breaks
Three nutrients for basic plant nourishment
Nitrogen, Phosphorous, Potassium
