Answer to Question #103359 in Chemistry for Riya

Question

Describe the various ways to find out the exact percentage of sand, silt and clay
particles in soil.

Answer 1

There are several methods use to estimate the soil texture.

The hydrometer method is based on the determination of the density of the soil suspension at certain intervals using a hydrometer. According to the results of the measurements, the diameter and the number of particles are calculated by the formula or using the nomogram. In a suspension, soil particles, fall to the bottom of the container, and the density of the suspension decreases. As the particles fall out, the hydrometer gradually sinks deeper and deeper into the suspension.

The pipette method is used to determine the particle size distribution of clay soils in combination with a sieve. This method is based on the separation of soil particles by their rate of fall in calm water. At certain time intervals, samples are taken from a suspension of soil from various depths, which are then dried and weighed.

Direct methods are based on the measurement of particles using optical and electronic microscopes.