Soil

Chemical Weathering

Breakdown of rocks through a change in their chemical makeup . This can happen when the minerals within rocks react with water , air or other chemicals

E- ( eluviated )

Leached of clay , minerals , and organic matter , leaving a concentration of sand and silt particles of quartz or other resistant materials

Nitrification of Ammonium

The use of fertilizers , especially those supplying nitrogen , has often been blamed as a cause of soil acidity .

Clay

Very sticky when wet , and can be molded into any shape and form . When they dry , they are rock hard .

Climate

affecting the rate of weathering and organic decomposition

Harvest of High Yielding Crops

its effect on soil acidity development because crops absorb the lime - like elements , as cations , for their nutrition .

Parent material

minerals forming the basis of soil

Pedogenesis

process of soil formation as regulated by the effects of place , environment , and history .

Base

substance that releases hydroxyl ions ( OH- )

Acid

substance that tends to release hydrogen ions ( H + )

Chalky

Alkaline with a pH of about 7.5 . Not acidic and often stony with chalk or limestone bedrock .

Soil Chemistry

Branch of soil science that deals with the chemical composition , chemical properties , and chemical reactions of soils .

Biological Weathering

Breakdown of rocks by living things .

Physical Weathering

Breakdown of rocks from the result of a mechanical action .

Living organisms

-influencing soil formation

R- ( bedrock )

A mass of rock such as granite , basalt , quartzite , limestone or sandstone that forms the parent material for some soils

Peaty

Acidic and as a result , does not support decomposition very well .

Widespread Pollution

Covers extensive areas and has several causes the reasons for which are difficult to identify .

Organic Matter Decay

Decaying organic matter produces H + which is responsible for acidity .

Soil Profile

Dig down deep into any soil , and you'll see that it is made of layers , or horizons ( O , A , E , B , C , R ) .

Acidic Parent Material

Due to differences chemical composition of _______ soils will become acidic after different lengths of time .

pedosphere

Earth's body of soil

Rainfall and Learching

Excessive rainfall is an effective agent for removing basic cations over a long time period .

Silty Soils

Finer , smoother in texture and holds water better than sandy soils .

Sandy Soils

Free draining , with the largest , but fine and hard particles . It has a gritty feel . It does not bind very well . Very low in nutrients .

Soil Formation

Made up mainly of mineral particles , organic materials , air , water and living organisms .

Soil pH

Measure of acidity or alkalinity of a soil .

Soil

Mixture of organic matter , minerals , gases , liquids , and organisms that together support life .

Loamy

Mixture of sand , clay and silt particles and has the ability to retain water .

A - ( topsoil )

Mostly minerals from parent material with organic matter incorporated . A good material for plants and other organisms to live .

O- ( humus or organic )

Mostly organic matter such as decomposing leaves . Thin in some soils , thick in others , and not present at all in others .

Specific Pollution

Occurring in small areas the reasons for which can be easily identified .

B - ( subsoil )

Rich in minerals that leached from the A or E horizons and accumulated here .

25%

Soil is made of about __ % air.

45%

Soil is made of about __ % minerals.

5%

Soil is made of about __ % organic matter.

25%

Soil is made of about __ % water.

Weathering of rocks

Soil is the thin layer of material covering the earth's surface and is formed from the ?

neutral

Soils with a pH of 7 are ?

alkaline or " sweet "

Soils with pH values above 7 are?

acid or " sour "

Soils with pH values below 7 are ?

Environmental Soil Chemistry

Study of chemical reactions between soils and environmentally important plant nutrients , radionuclides , metals , metalloids , and organic chemicals .

C- ( parent material )

The deposit at Earth's surface from which the soil developed .

Clay

The particles that make up ______ are the finest and they bind very well

Topography

grade of slope affecting drainage , erosion and deposition

Time

influencing soil properties

Soil Acidity

involves intensity and quantity aspects . The intensity aspect is universally characterized by the measurements of H + ion activity , expressed as pH .