All about Soil and Aggregate Impact Tester
Together, soil texture and soil structure are the greatest
influencing factors on pore space in a soil. It is what determines how easily
air, water, and roots can move through a soil. A lot of people are aware of
what soil texture – proportions of sand, silt and clay – they are dealing with
however not many people take a soil’s structure into consideration though, even
though in most soils, the structure is equally important.
Two soils with the same
texture can behave very differently depending on their structure. Clay soil,
for example, would be easy for air, water, and roots to move through with good soil structure, or be almost
impenetrable by roots, air, and water when the structure has been completely
destroyed by compaction.
Soil structure refers to how
particles of soil are combines together into such aggregate
impact testers. They are either cemented or bound together through
various physical, chemical, and biological processes.
There are a number of causes
that may lead to the deterioration of soil structure. Some of those factors include compaction,
cultivation, removal of vegetation, excessive moving and handling of soil, screening,
excessive sodium, etc.
Some of the demanding
aggregates are (i) Aggregate impact tester - it consists of two vertical guides
which has a circular base. The weight of hammer is 13.75 +- 0.25 kg that can be easily
raised for free fall. The height of fall can be adjusted through 380-+ 5 mm. (ii)
Aggregate crushing value - used to find unit weight of aggregates or bulk
density. It includes three measures 3 litres capacity, 15 litres capacity and
30 litres capacity.
A large proportion of sodium
to calcium and magnesium would cause clay particles to repel each other when
they are wet. This result in having the aggregates
dispersed. The process of soil structure formation gets reversed. Soils that
have too little sodium become almost impermeable to water. This is because the
dispersed clay and small organic particles would clog up remaining soil pores.
Excessively high sodium levels would be caused by irrigation and salting roads.
It is important to make sure
a good soil structure is retained. As the USDA Natural Resources Conservation
Service (2008) explains, “Practices that provide soil cover, protect or result
in the accumulation of organic matter, maintain healthy plants, and avoid
compaction improve soil structure and increase macro pores.” Among other key
practices to preserve soil structure are eliminating soil screening and minimising handling, as well as avoiding use of sodium salts.
Soil structure can be
classified by type (shape), class (size) of peds, as well as grade (strength of
cohesion) of aggregates. Shape, size, and strength of aggregates are a key
factor in the determination of the pore structure, as well as how easily air,
water, and roots would move through soil.
Columnar structure is the
structure that is usually found in soils that have excessive sodium, because of
the dispersing effects of sodium that destroys soil structure, while also
rendering the soil sealed to air as well as water movement.
Platy structure is the
structure that has the least amount of pore space and is common when compared
to compacted soils.
There are some soils that
have no true structure. They include single grain soils (like a loose sand with
little to no attraction between the grains of sand), as well as massive soils
(large cohesive masses of clay).
You can buy good quality soil
testing equipment online.
Online shopping portals like Bellstone
Online have excellent soil
testing equipment including
the incredible Aggregate which you can buy at affordable prices.
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