Soil Structure Berbagai Macam Struktur Tanah

 

Soil Structure 

 

Soil Structure •

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Individual sand silt and clay particles will form together into specified shapes. These shaped structural peds  are given names based on their appearance. –

Peds are formed in the soil by wetting, drying, freezing and thawing and are heldmatter by clay and organic

 

Kinds of Soil Structure •

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Granular Platy Sub-angular Blocky Prismatic Good structure  promotes healthy soil

 

Soil Structure  •

Soil separates do not act in the soil as individuals, but as partners, or aggregates. Aggregates are the clumps of soil separates.

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When aggregates are bound into larger masses they are called . PEDStogether soil structure is relatively easy to change or alter especially when the soil is being cultivated. Soil clods can be broken apart by wetting and drying, and by freezing and thawing. Cementing agents which bind soil separates together include microbial gums, iron oxides, organic matter, and clay.

 

Types of Structure

 

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Granular Structure 

 

Granular Structure •

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Granular structure is the most beneficial form of soil structure for plant growth. Granular structure aggregates are formed by the breaking apart of aggregates through physical processes of wetting andlarger drying, and freezing and the thawing.  These aggregates are then cemented cemented together by the by-products by-products of the microbial decomposition of organic matter, which are called microbial gums.  The more microbial gums, the greater the the aggregate stability. The  way to obtain microbial gums is by adding organic matter to the soil; thus, plant residues contribute indirectly to better soil structure

 

2. Platy Structure 

 

Platy Structure •

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Platy structure is often found in the E horizon (below the A) where water moves laterally through the soil. Platy structure can be detrimental because it restricts root and water penetration.

 

3. 3.  Blocky Structure 

 

Blocky Structure •

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Blocky structural peds are found most frequently in the B horizons.  They have been created by the wetting and drying and freezing and thawing cycle of the B horizon.  The clay films also act as a binding agent for the blocky aggregates.  The B horizon can often be determined in a profile by looking for the location of blocky peds which can be readily seen. Blocky can be either angular (sharp ped edges) or subangular (rounded ped edges).  edges). 

 

4. Prismatic or Columnar Structure

 

Prismatic or Columnar Structure •

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 Where the blocky peds are longer than they are  wide, the prismatic or columnar structure is identified (common only in B horizons).  They are often the first structure formed in a soil, because their formation only requires  vertical cracking in the soil.

 

5. Structureless 

 

Structureless •

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C horizons generally lack any structural aggregation.  Their lack of structure is termed "massive." Massive structure is hard to break apart and appears in  very large clods.  Where very sandy soils lack aggregation, or the th e soil particles don't stick together the structureless condition is termed "single-grained." Single grained always accompanies a loose consistence.