All about Soil and Aggregate Impact Tester

by Hemant Sharma Digital Marketing Manager

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.