Definition of soil and soil profile, its division

Welcome to agriculture exam. Here  we define of soil and soil profile with all details.

What is Definition of Soil 

 The life of animals and plants directly or indirectly depends on the earth because everything of their need is received by the soil in some way or the other.

 The word Soil originates from the Latin word 'Solum' which literally means floor. In this way, the soil is called the top floor or layer of the earth.

According to the great Swedish scientist Berzelius, "Soil itself is a vast laboratory of nature in which a variety of complex chemical decomposition and analysis reactions in the womb are carried out continuously by plants and bacteria."

Many soil chemists have given definitions of soil from their perspective. The definition of soil is as follows.

 " The soil is defined as a natural body, synthesized in profile from a variable mixture of broken and weathered minerals and decaying organic matter, which cover the earth in a thin layer and which supplies when containing the proper amount of air and water, mechanical support and in part, sustenance for plants. "

What is Soil Profile?

Soil is formed after the physical, chemical, and biochemical forces of the earth's rocks are decomposed. In the soil formation process, if the climate and the rays of the sun are properly coordinated, then different layers are formed in it.

 " After cutting a land from top to bottom or cutting the ground, different layers of seasonally degraded root material are found from top to bottom. The vertical part or cut of all those layers is collectively called the Soil Profile."

" Layers of soil erosion, which appear to be distinct or similar or can be identified by the analysis, are called horizons. "

 A well-developed soil has many strings which differ greatly in physical and chemical properties from one to the other. Soil erosion can be divided into the following horizons.

1.  A  Horizon 

A layer of soil begins at the topmost surface of the soil where the roots, leaves, and roots of plants accumulate. 

In this stratum, a variety of chemical substances go down with water latching, hence it is also known as the alluvial horizon. This horizon is divided into the following subdivisions -

A° Horizon 

 Due to the presence of partially dissolved organic matter in this sub-horizon, its color is black or drab. Sub-horizon is clearly found in the soils of forests under this stratum. One is fermented and the other is humified.

A°° Horizon 

 In this sub-horizon, a large amount is found in the form of unclothed organic matter decomposition.

A1 Horizon 

It is a horizon of mineral substances with dark black color. It has the predominance of mineral substances which are found in a mixed state with humus obtained by dissolution of organic materials.

A2 Horizon 

 It is a highly developed light-colored mineral horizon and is formed due to partial exudation of basic substances through leaching and bleaching reaction.

A3 Horizon  

 It is absent in most soils. It is a transitional layer present between the A and B horizon.

2.  B Horizon 

           This horizon is the sub-soil found under the horizon A. The organic and inorganic materials of A horizon reach and accumulates in this stratum through leaching, hence it is called Accumulation or Elluviation stratum.

 Under this, excess of iron and aluminum oxide and silicate is found. It is divided into the following sub-horizons.

 B1 Horizon  - It is an interstitial horizon between A and B similar to A3 which is absent in most soils. Its color varies from black to brown.

B2 Horizon - Due to the presence of iron and aluminum oxide in this horizon, its color varies from Badami to Reddish-brown.

B3 Horizon - It is an interstellar layer between B and C that is not fixed in its presence.

3. C Horizon 

This horizon is also called the root or ancestral horizon. In this part, the original soil material is found in a less dissolved state, which can often be similar to or even different in levels A and B in physical, chemical, and biological properties.

 This level cannot have any relation to the soil while horizon A and B have a close relationship with each other.

Below the horizon, C are base rocks which are also called organized base rocks. All the unorganized materials present above the base shell which is organic and phosphatic together are called the Regolith.

 Regolith varies in thickness from a few cms to thousands of meters depending on appearance. The thickness of the regolith is dependent on soil formation factors. The strings A and B present above the parent material is called solum together.

  Major Constituents of Soil

 The organization and configuration of any two soils are generally not the same. Generally, four major components are found in mineral soils.

(1)Mineral matter --  45%
(2) Organic matter -- 5%
(3) Soil water --  25%
(4) Soil air -- 25%

Mineral Matter or Inorganic Matter 

The mineral content of the soil is formed due to physical and chemical weathering in the original rocks. It is usually found in the mineral soil by 45 - 50%. Soil is divided into four parts based on particles of mineral substances.

(a) Very coarse- Stones and gravels come under it. It is a piece of soil whose size is larger than 2 mm.

 (b) Coarse - Under this comes thick sand and fine sand. Their particles range in size from 0.02 - 2.0 mm. Due to the size of the sand particles, they can be seen with open eyes. Due to its presence, the soil feels brown to the touch.

(c) Fine - It consists of silt particles whose size is between 0.002 - 0.02 mm. Large particles of silt can be seen with open eyes, but fine particles are visible only by microscope. These are fine flour to touch.

( d ) Very fine  - It consists of clay whose particles are smaller than 0.002 mm in size. The size of their particles is smaller than silt.

From a chemical point of view, 90 percent of the mineral content is made up of silica (SiO2), alumina (Al2O3), and iron oxide (Fe2O3). 

The remaining 10 percent is found to contain Ca, Mg, K, Ti, Na, N, S, P, B, Mn, Zn, Cu, I, CI, and other types of elements. On the basis of percentage, the quantity of minerals is found as follows.

SiO2 = 76%,   Al2O3 = 12%,    Fe2O3 = 3%,   K2O = 2%,    Cao = 1%,   Mgo = 1%

All other types of elements are = 3%.

  Soil Organic Matter 

In addition to mineral material, organic matter is also found in the soil. Soils in which organic matter is found to have more than 20 percent organic matter and organic matter containing less than 20 percent are called mineral soils.

 The amount of organic matter in the top layer of soils is higher than in the lower surfaces. The amount of organic matter in the upper surface is often found in 1-6%. 

Its average volume is 3%. Organic material refers to the dead or living remains obtained from the flora and fauna that are found in the soil in any way, so many types of dead and living substances which are found in the soil in any way from the plants and animals, they are called organic matter or organic matter.

The supply of organic matter in the soil continues continuously through various remnants of trees - plants such as root, stem, branch, leaf, flower, and fruit.

 Similarly, feces - urine and dead bodies of animals and animals continue to be found in the soil. These substances of flora and fauna get converted into new substances after decomposition by microbes due to which the soil color becomes dark brown.

 These new substances are called Jivansh and they have an important place in agriculture.

 Organic materials of the soil are particularly high in undissolved or partially decomposed residue material of the vegetation. In addition, living and dead animals and microorganisms are also found in small amounts.

 Complete decomposition of the above organic matter of the soil produces a black or brown colored colloid substance called humus. Its water holding capacity is high. 

All types of nutrients required for plant growth and development are available in humus. In this way, the organic matter of soil has a very important place in plant growth.

  What is Soil Air 

Soil Vayu refers to the air that is found in the holes (particles) of the soil particles. The percentage of air in the soil is related to the amount of soil water.

 Air-rich soils are less airy and dry soils are more. Soil air contains O2 = 20.00 percent, N2 = 79%, CO2 = 0.15 - 0.65%.

The atmosphere contains 20% of O2 and 0.03% of CO2, ie the soil has less O2 and more CO2 than the atmosphere. The amount of CO2 in the soil air is high due to the rotting of organic matter, melting and respiration by roots. Due to the constant use of oxygen by the roots of plants and by microorganisms, the amount of oxygen in the soil air is less than that of atmospheric oxygen.

 Soil Reaction

 Soil reaction refers to the acidity, alkalinity, and neutrality of a soil solution. Soil reaction mainly depends on different types of ions present in the soil solution. Some of these ions are acidic in nature example H+NO3-SO₄²- Etc. and some are alkaline in nature like- OHCa++Mg+2Na+K+, Etc., but acidification of soil solution is mainly due to H+ and alkalinity OH.

 The concentration of H+on the surface of a soil colloid is acidic when it is higher than OH and if the concentration of OH is higher than that of H+, the soil is alkaline in nature. Soil is neutral when both ions H+ and OH are equal. Thus it is clear that the soil reaction is primarily based on the concentration of hydrogen ions.

The amount of acid and alkalinity of soil can be expressed as low (moderate), medium, high, or strong. To find the reaction of soil. Determine the ratio of H+ and OH present in it and its nature i.e. acidic, alkaline, and neutral states based on their proportional amounts. Soil is divided into three parts based on the concentration of H+ present on the colloidal narrow of the soil.

 (1) Acidic soil (2) Neutral soil (3) Alkaline soil

Hydrogen ion concentration or pH

 The scale used to express soil reaction is called pH. pH is a series of numbers in which the numbers 0 to 14 are sorted. By which the acidity and alkalinity of all types of solutions can be measured. Pure distilled water is completely neutral at a temperature of 25 ° C and its pH is 7. Is 0. In this case, it has the same concentration of H + and OH−. In the PH scale, as the values ​​go from 7 to 0, the acidity increases and as the values ​​go above 7, the alkalinity of the solution increases.

First of all, in 1909, S. P. Sorensen, a Danish biochemist, invented a very simple and suitable method to express the concentration of hydrogen ion of a solution called PH value. is. In  (pH), it prefers to the concentration of Reciprocal power or Strength, and H refers to the concentration of hydrogen ion. Sorenson expressed the concentration of hydrogen ion of a solution in 10-x grams per liter, instead of just the letter x, ie the pH of a solution is the minus exponent of base 10. In this way, the concentration of hydrogen ion in a solution is expressed in grams per liter when the negative x is raised to 10.

 Amorphous solutions are those solutions in which there is no increase in the acid or alkalinity of a solution by adding acid or alkali, that is, the solution is called amorphous solution whose acidic and alkalinity are reserved and this process is called amphoteric action. This property of these solutions is due to their reserve acidity and alkalinity.

The definition of the buffer solution is as follows.
"A solution in which even a small amount of an acid or alkali solution is added does not change its pH value, ie their acidic or alkalinity is reserved. The buffer solution is called.

Definition of buffer solution based on composition

"The amphibious resistance solution is its salt made with a weak acid and strong alkali or its salt made with a weak acid and strong acid."

There are two types of buffer solution:

 ( 1 ) Acidic buffer solution - Such as acetic acid and sodium acetate, citric acid and sodium citrate, phosphoric acid and sodium phosphate, carbonic acid and sodium carbonate, etc.

( 2 ) Alkaline buffer resistant solution  Ammonium hydroxide and ammonium chloride.

Acidic soil
When the hydrogen ions (H +) are more than the hydroxyl ions in the soil, it is called acidic soil.  This property of soil is called Soil acidity.  In acidic soils, H + is found in two forms 
 As a soil solution and in the absorbed state on the surface of the colloidal complex.  An equilibrium is found in both of which the ratio of H + and OH− in the soil solution keeps changing.

 The acidity that is found due to the H + present in the soil solution is the acidity found due to the active acidification and the H + absorbed on the colloidal complex is called the reserve acidity.

A.  Effect of soil acidification on plant growth
 (a) Direct Influence
 1. H + toxic effects present in acidic soil on the roots of plants.
 2. The balance between the phosphonium and acidic components found in the roots becomes changed. 
3 There is a bad effect on the permeability of the hearts in the roots. 
4. Angamed enzymes have a bad effect on the plants.

( b ) Indirect effect
1. Due to more acidity, the availability of CA, MG, K is reduced to plants. 
2. Fe, Ai, and Zn's availability becomes so much more on acidity that they become toxic. 
3. The acceleration of P decreases to more acidity. 
4 more acidity and the number of micro bacteria and stirring increases. 
5. There are many diseases in plants with more acidity.

B. Acidic soil
1. Mercury of soil in heavy rainfall 
2. Using acids generating fertilizers 
3. The stirring of micro bacteria 
4. Marine constructed by acidic original rocks.

 C. Improve acidic soils 
( 1 ) By using Lime - Caco3, Mgco3, Cao, etc. (2) by using the use of Bhasakbar fertilizers - calcium nitrate, calcium ammonium nitrate, Bhaskar metal stool, sodium nitrate, potassium fertilizer, calcium-sanemide, etc.

D. Crops that bear soil acidity
 1. Potatoes, Paddy, Oats, Rai, Shakrakand soil growing crops can be more acidity.
 2. Wheat, barley, turnip, grass, oats, etc. Eat medium acidity. 
3. Carrots, peas, tomatoes, eggplants and corn, soybeans, etc. bear less acidity.
 4. Can not bear the acidity of beans, cabbage, tide, melon, onion, etc.

 Saline and Alkali Soil 

 A.  Saline Soil 
Hilgard gave these soils named White Omor (White Alkali) and Gedaris' Solan Chak Solon Chak'.

 " They are more than 15% of the soil, which are more than 15% and discharged sodium is less than 15% and P-H08. Less than 5, saline softness is called. "

The amount of soluble salts is high in these soils. Soluble salts have a prominence of NACL and NA2SO4. CA & MG CO3-. SO4--, HCO3-, are also present in substantial quantities.

B.  Alkali Soils 
 " They are less than 15% of the electrical conductivity of the saturated conclusion of soil at 25 ° C and the amount of exchange sodium is more than 15%. And P-H8 5 - 10 occurs, alkaline soils are called.

 Hilliard has named its name Solonetz by Black Alkali Soil and Galeries. In these soils, the soil is saturated with narrow NA, as well as CA, MG, K, etc. are also notorious. In the debt, CO3-- is the preference but Ci-, SO4--, HCO3- are also found.

C. Reclamation of Saline and Alkaline Soils 
 Whatever prevalent methods to improve salination and alkaline soils, we classify them in the following sections -
 (a) physical methods,
 (b) chemical methods,
 (c) organic methods.

( a )  Physical Method 
Under the physical methods, the eradication of soil salts and their expansion is controlled. Under this, the following methods are --
( 1 ) ( Scraping of salts )
( 2 )  ( Leaching of salts )
( 3 )  ( Drainage )
 ( 4 )  ( Washing out of salts )
( 5 )  ( Trenching )
( 6 )  ( Control on evaporation )

( b ) Chemical method 
 The more harmful sodium salts present in the soil by the use of chemical reformers are converted into less harmful salts such as calcium salts. Thus soil reformers can be divided into the following parts ---
 ( 1 ) Solidays Calcium Salts - For example, calcium chloride, gypsum (Caso4. 2H2O), and phosphogypsum.
 (2) Low solving calcium salts - Limestones, suggestive lime substances obtained from sugarcane mills. 
(3) Acid and acid producer - Sulfur, Sulfur's acid, fluid sulfur, die - oxide, AL2 (SO4) 3, FESO4, Lime Sulfur, and Pyrite.

 ( c )  Biological reclamation 
 Studies of biological reforms are done in the following sections.
 ( 1 ) Use of molasses 
 ( 2 ) Press Mud
( 3 ) Green manure, compost other organic food, and relics
( 4 ) Use of flora

D. Integrated programs and crop arrangements for improving salinity and alkaline soils
( 1) Using salinless irrigation water. 
(2) Strong mediba 
(3) Samplanization 
(4) Irrigation and more quantity.
 (5) Good governance of water exhaust
 (6) Using soil reformers after soil testing. 
(7) Maximum utilization of organic fertilizers and residues 

 Use of Pyrites,( Fes2)
Pyrite is a flammable substance. When mixing it in the soil, it immediately reacts to air and water. This is available in the form of accent, flaky and powdered. Pyrite is available as powdered. The most useful and active. The amount of pyrite mixed in saline and alkaline soil is based on soil salinity, alkalinity, and soil structure.

It is necessary to torture the soil by flattening the soil before mixing the pyrite. About 2 tonnes of pyrite per acre in P-H 9 soil should be made and irrigating. On drying of the farm, almost a week should continue to synchronize. Its action is completed in 7 - 10 days. This is a cheap, accessible, and best soil reformer. When mixing it in the soil makes it sulfuric acid and ferrous sulfate from the contact of air and moisture because it is an Iron and Sulfur (FES2.) Compound Sulfur.


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