Bodenfraktion

Bodenfraktion refers to the process of separating soil into different particle size classes. These classes, often termed soil texture fractions, are typically sand, silt, and clay. The proportions of these fractions determine the soil's texture, which in turn significantly influences its physical, chemical, and biological properties.

Sand particles are the largest, ranging from 0.05 to 2.0 millimeters in diameter. They contribute to good drainage and aeration but have low water and nutrient holding capacity. Silt particles are smaller, measuring between 0.002 and 0.05 millimeters. Silt-sized particles have a texture that feels smooth or floury when dry and slippery when wet. They offer a balance between drainage and water retention. Clay particles are the smallest, less than 0.002 millimeters in diameter. Clay has a large surface area, which allows it to hold water and nutrients effectively, but it can also lead to poor drainage and compaction.

The determination of Bodenfraktion is crucial in soil science, agriculture, and environmental engineering. It is typically performed using methods like sieving for larger particles and sedimentation (e.g., the hydrometer method or pipette method) for finer particles based on Stokes' Law. Understanding the soil texture composition helps in predicting water infiltration rates, runoff potential, susceptibility to erosion, and suitability for various crops or construction purposes. Different soil texture classes, such as sandy loam, silty clay, or loam, are defined by specific combinations of these fractions.