Soil Resources Flashcards
define soil
soil is the thin layer of loose mixture of small rock particles and rotting organic matter that covers the surface of the earth
process of soil formation
pedogenesis
study of soil and its associated factors
pedology
characteristics of fertile soil
- adequate amount of moisture
- sufficient depth to enable plants to grow their roots
- rich in nutrients
- contains organic matter
categories of soil
- In-situ (residual/sedimentary)
- ex-situ (transported soil)
in-situ soils
red soil, black soil, laterite soil, desert soile
example of transported soils
alluvial soil
Alluvial Soil
- formed by sediments brought down by rivers
- fine particles called alluvium
- aka riverine soil
- mixture of clay, sand, silt (loam)
where is alluvial soil formed
indus, ganga, brahmaputra
coastal in coastal plains and deltas of mahanadi, krishnam godavari, kaveri
two types of alluvial soil
bhangar and khadar
bhangar soil
old, composed of lime nodules (kanker),clayey composition
khader soil
light colour,
newer deposits,
more fertile as new layers of soil are deposited after monsoons
distributions of alluvial soil
- inland: indus, ganga, brahmaputra
- deltaic: ganga-brahmaputra delta, mahanadi, godavari, kaveri, krishna
- coastal: peninsular india, gujarat
GR: why does alluvial soil differ in colour?
- depth of deposition\
- texture of materials
- time taken for maturity
texture of alluvial soil
upper reaches: dry, course, porous, sandy. has clay and organic matter, large and non uniform soil matter (piedmont plains)
lower: particles are uniform and small, moist, depth of 500 m
minerals in alluvial soil
LFMPA: lime, iron, magnesia, potash, alumina
deficient in nitrogen and hummus
more alkaline in drier areas
crops on alluvial soil
rice, wheat, sugarcane, cotton, tobacco, gram, !!jute!!
name of black soil
black cotton soil/ regur soil/ lava soil (formed by denudation of volcanic rocks)
distribution of black soil
deccan lava tract
texture of black soil
fine textured
caleyey
high water retentivity
difficult to plough