The aggregate stability of a soil is the resistance of soil structure against mechanical or physicochemical 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 farmers.
Soil structure is defined by the combination or arrangement of primary soil particles into compound elements, which are separated from adjoining structural elements by surfaces of weakness. Soil texture, soil structure, and the type of clay mineral, organic matter content and type, cementing agents and cropping history influence the aggregate stability.
Among the mechanical destructive forces are soil tillage, impact of heavy machinery, treading by animals and raindrop splash. Physico-chemical forces are e.g. slaking, swelling and shrinkage, dispersion and flocculation.
Slaking is the process of structure breakdown under the influence of wetting of soil aggregates, due to swelling of clay minerals, dissolving of cementing agents, air explosion or reduction in pore water suction. Slaking may result in the formation of a superficial crust, reducing water infiltration and enhancing sediment loss by downward transportation with surface runoff water.
| Maximum number of samples |
8 |
| Measured parameters |
Aggregate stability |
| Measuring range |
0 - 100% |
| Power supply |
line voltage |
| Reading accuracy |
Depending on weighing equipment |
| Sample specification |
disturbed |
| Voltage |
110 - 240 volt |
|