Objective:
This topic gives an overview of;
Teeming with Life
Types
Percolation Rate of Water in Soil
Moisture in it
Absorption of Water by it
this And Crops
Soil
Soil is one of the most important natural resources. It supports the growth of plants by holding the roots firmly and supplying water and nutrients. It is t he home for many organisms. it is essential for agriculture. Agriculture provides food, clothing and shelter for all. it is thus an in separable part of our life. The earthy fragrance of it after the first rain is always refreshing.
Activity
Collect some soil samples and observe them carefully. You can use a handlens. Examine each sample carefully. Make a list of the uses of soil.
Polythene bags and plastics pollute the soil. They also kill the organisms living in the soil. That is why there is a demand to ban the polythene bags and plastics. Other substances which pollute the soil are a number of waste products, chemicals and pesticides.
Activity
Take a little soil. Break the clumps with your hand to powder it. Now take a glass tumbler, three quarters filled with water , and then add a handful of soil to it. Stir it well with a stick to dissolve the soil. Now let it stand undisturbed for some time. The rotting dead matter in the soil is called humus . You probably know that the soil is formed by the breaking down of rocks by the action of wind, water and climate. This process is called weathering . The nature of any soil depends upon the rocks from which it has been formed and the type of vegetation that grows in it.
A vertical section
A vertical section through different layers of the soil is called the soil profile . Each layer differs in feel (texture), colour, depth and chemical composition. These layers are referred to as horizons .
A vertical section through different layers of the soil is called the soil profile . Each layer differs in feel (texture), colour, depth and chemical composition. These layers are referred to as horizons .
We usually see the top surface of the soil, not the layers below it. If we look at the sides of a recently dug ditch, we can see the inner layers of the soil, too. Such a view enables us to observe the soil profile at that place.
The best topsoil for growing plants
The best topsoil for growing plants is loam. Loamy soil is a mixture of sand, clay and another type of soil particle known as silt . Silt occurs as a deposit in river beds. The size of the silt particles is between those of sand and clay. The loamy soil also has humus in it. It has the right water holding capacity for the growth of plants.
it is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life . Earth’s body of soil, called the pedosphere, has four important functions:
Activity
Collect samples of clayey, loamy and sandy soils. Take a fistful of soil from one of the samples. Remove any pebbles, rocks or grass blades from it. Now add water drop by drop and knead the soil. Try to make a ball from this soil. On a flat surface, roll this ball into a cylinder . Try to make a ring from this cylinder. Repeat this activity with other samples also.
how to calculate percentage of water absorbed by soil
Properties of Soil
You have listed some uses of soil. Let us perform some activities to find the characteristics of the soil.
Percolation Rate of Water in Soil
Boojho and Paheli marked two different squares of 50 cm – 50 cm each, one on the floor of their house and the other on the kutcha (unpaved) road. They filled two bottles of the same size with water. They emptied the water from the bottles, one each, at the same time in the two squares.
Soil is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Earth’s body of soil, called the pedosphere, has four important functions:
All of these functions, in their turn, modify the soil and its properties.
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earth or dirt
Soil is also commonly referred to as earth or dirt ; some scientific definitions distinguish dirt from soil by restricting the former term specifically to displaced soil.
The pedosphere interfaces with the lithosphere, the hydrosphere, the atmosphere, and the biosphere.[1] The term pedolith , used commonly to refer to the soil, translates to ground stone in the sense fundamental stone , from the ancient Greek πέδον ground , earth . Soil consists of a solid phase of minerals and organic matter (the soil matrix), as well as a porous phase that holds gases (the soil atmosphere) and water (the soil solution).[2] [3] Accordingly, soil scientists can envisage soils as a three-state system of solids, liquids, and gases.[4]
Soil is a product of several factors: the influence of climate, relief (elevation, orientation, and slope of terrain), organisms, and the soil’s parent materials (original minerals) interacting over time .[5] It continually undergoes development by way of numerous physical, chemical and biological processes, which include weathering with associated erosion. Given its complexity and strong internal connectedness, soil ecologists regard soil as an ecosystem.[6]
resource: wikipedia
how to calculate percentage of water absorbed by soil
