concept of soil science

1. Presented by:- Seema prajapat
AGRICULTURIST
Concepts and definitions of
soil

2. Concept:
► Soil as a verb it means ‘ to make dirty as in case of soiled dishes or
clothing.
► The noun soil is derived through Latin word solum,which means floor or
ground.
► Soil scientist calls SOIL,
A geologist calls FRAGMENTED ROCK,
an engineer calls EARTH,
an economist calls LAND.
► Whitney developed the concept of soil as a nutrient bin.

3. Two basic concepts of soil
► The first one soil as a natural body,
a biochemically weathered and synthesized product of nature.
► Second soil as a natural Habitat for plants and other living organisms.
► PEDOLOGY :study of origin of the soil,it’s classification and it’s description.
► EDAPHOLOGY:study of soil in relation to growth ,nutrition and yield of crops.

4. Defination of soil :
► Soil are applied solely to those suerificial horizons of rocks,that have been
more or less modified naturally by the interaction of water,air and various
kinds of organisms, either living or dead;this being reflected in a certain
manner in composition,structure and colour of such formations.where this
conditions are absent, there are no natural soils,but either ARTIFICAL
MIXTURE OF ROCKS.
-DOKUCHAEV.
► “SOIL IS A NATURAL BODY DEVELOPED BY NATURAL FORCES ACTING ON
NATURAL MATARIALS. It is usually differentiated into horizons from mineral
and organic constituents of variable depth which differ from the parent
material below in morphology,physical, chemical and biological properties.
-JOFFE AND MARBUT.

5. ► “Soil is the more or less loose and crumbly part of the outer earth crust in
which;by means of their roots, plants may or do find foot hold and
nourishment as well as all other conditions essential to their growth.
-HILLGARD.
► Soil may be defined as “A DYNAMIC NATURAL BODY on the surface of the
earth in which plants grow,composed of mineral and organic materials and
living forms.
- BUCKMAN AND BRADY.

6. soil science:
The soil science following well defined discilpines:
► SOIL FERTILITY-
- Refers to the nutrient supplying properties of the soil.
- The nutrient requirement of plants,the supply of nutrients by the
soil,ways in which nutrients are lost From the soil,and method by
which soil fertility may be restored.
► SOIL PRIDUCTIVITY-
- Is the capacity of a soil,in its natural environment,to produce crops
under a specified system of management,and is expressed in terms of
yield.

7. ► SOIL CHEMISTRY-
It is a devision of soil science concerned with the chemical
constituents,the chemical properties and the chemical
reaction of soil.it is the study of chemical composition of soil in
relation to crop needs.
► Soil physics-
soil physics is a devision of soil science that involves the
study of physical properties of soil.temprature,pressure,light etc.

8. ► Soil microbiolog-
it is a division of soil science that deals with microscopic population
of the soil,it’s role in various transformations and it’s importance
in plant nutrition,decomposition and crop production.
► Soil conservation-
it is a division of soil science dealing with the protection of soil
against physical loss by erosion or chemical deterioration or
degradation by natural or human induced factors.
It is the management of soil with the purpose of producing high
yields and at the same time,protecting it from degradation.

9. ► Pedology-
study of soil genesis,survey and classification and the law
of geographic distribution of soils as a body in nature.
pedography- description
pedogenesis- origin of soil or soil genesis.
► Soil survey-
soil survey comprises morphological examination,description
classification and mapping of soils in their natural
environment for interpretation and correlation.

10. ► Soil classification-
It is a process of logical grouping based on the properties
and characteristic of representative units of natural
bodies,viz soils.the taxonomic units are frequently
regrouped for various purposes,such as drainage
requirements,crop growth,highway construction
forestry etc.
Thank you