The wet sieving apparatus is used to determine the aggregate stability of a soil, which is the resistance of soil structure against mechanical or physico-chemical destructive forces.
Soil structure is one of the main factors controlling plant growth by its influence on root penetration, soil temperature and gas diffusion, water transport and seedling emergence and therefore it is an important soil characteristic for growers.
The standard set includes a shaking machine for wet sieving method (incl. 100-240 VAC adapter). Suitable for 8 sieves, aluminium cans – 62.5×44 mm, sieve cans – 39×39 mm with sieve opening 0.250 mm and sieve surface of 10.2 cm2.
8 Sieves: Aluminium cans – 62.7X44 mm, sieve cans – 39X39 mm
Weight: 19.85 lbs.
Dimensions: 24 x 16 x 16 inches
Due to the impact of aggregate stability on plant growth and soil loss, applications of the wet sieving apparatus are the fields of agriculture and land conservation. This method to determine aggregate stability will be especially useful for researchers and scientists on soil erosion, land degradation and conservation, agriculture, sustainable agriculture.
Scientists on salinisation problems may have advantages determining wet aggregate stability using wet sieving, to control deterioration of soil structure or to determine possible impacts of amelioration practices on aggregate stability.
Determining aggregate stability will give information on the sensitivity of soils to water and wind erosion, which might be prevented e.g. by mulching the soil surface. Information on soil aggregate stability will improve tillage programs, adapted to the specific soil type and crop demands.
The wet aggregate stability is determined on the principle that unstable aggregates will break down more easily than stable aggregates when immersed into water.
To determine the stability, 8 sieves (with 60 Mesh screen) are filled with a certain amount of soil aggregates. These sieves are placed in a can filled with water, which will move up and downward for a fixed time. Unstable aggregates will fall apart and pass through the sieve and are collected in the water-filled can underneath the sieve.
After this fixed time, the cans are removed and replaced by new water filled cans. Now, all aggregates are destroyed. Sand grains and plant roots will remain on the sieve and only aggregates are considered. After drying the cans with the aggregates, the weight of both stable and unstable aggregates can be determined.
Dividing the weight of stable aggregates over total aggregate weight gives an index for the aggregate stability. To prevent slaking of the aggregates when putting the filled sieves into the water filled cans, the aggregates are pre-moistened with water vapour, using a humidifier or a very fine plant sprayer.