What methods are used to determine soil texture?

Soil texture is a classification instrument used both in the field and laboratory to determine soil classes based on their physical texture. Soil texture can be determined using qualitative methods such as texture by feel, and quantitative methods such as the hydrometer method.

How do you use the hydrometer method?

To use the hydrometer, fill the hydrometer jar with the sample liquid. Place the hydrometer in the jar and give it a quick twirl to dislodge any air bubbles. Once the hydrometer has settled, take the reading from the appropriate scale. In order for the measurement to be accurate, the sample liquid must be at 60°F.

What is hydrometer analysis of soil?

The hydrometer analysis of soil, based on Stokes’ law, calculates the size of soil particles from the speed at which they settle out of suspension from a liquid. Results from the test show the grain size distribution for soils finer than the No. 200 (75µm) sieve.

What is Bouyoucos hydrometer method?

In the methodology proposed by Bouyoucos, the size of the solids in the suspension is estimated from the density of the solution measured using the hydrometer. The Pipette method and the method proposed by Bouyoucos differ in the treatment of the samples before sedimentation.

What is textural classification of soil?

Table 2.1. Soil separates and textural class

What are the three types of soil texture?

Soil Texture The particles that make up soil are categorized into three groups by size – sand, silt, and clay. Sand particles are the largest and clay particles the smallest. Most soils are a combination of the three.

How do you perform a hydrometer analysis of soil?

Stir the soil suspension for about 15 minutes. Transfer the suspension to the Hydrometer jar and make up the volume exactly to 1000 cc by adding distilled water. Take another Hydrometer jar with 1000cc distilled water to store the hydrometer in between consecutive readings of the soil suspension to be recorded.

What is CU and CC?

The uniformity coefficient (Cu) and the coefficient of gradation (Cc) are the measures of soil gradation. These coefficients help to classify the soil as well graded or poorly graded ones.

What is the hydrometer method?

Hydrometer method is used to determine the particle size distribution of fine-grained soils passing 75 µ sieve. The hydrometer measures the specific gravity of the soil suspension at the center of its bulb. The specific gravity depends upon the mass of solids present, which in turn depends upon the particle size.

How is soil texture measured with a hydrometer?

In the Bouyoucos_M method, the soil organic matter (SOM) was destroyed and the dispersingagent concentration was increased. In the Bouyoucos_M-T method, the sand was quantified gravimetrically by sieving samples through a 53 µm mesh. The hydrometer and Pipette methods measurements correlated well.

Can a hydrometer be used for organic soils?

Hydrometer method cannot be used for saline or organic soils or for soils which are known to be difficult to disperse. It also gives anomalous results with calcareous soils as the method does not involve any pre-treatment with hydrochloric acid to remove the calcium carbonate.

How is the textural class of soil determined?

The common field method for determining the textural class of a soil is by its feel. It is of great practical value and depends upon the skill and experience of the worker. The principle underlying the determination of soil texture by this method is based on the properties, which the soil components exhibit.

What is the hydrometer method for sedimentation analysis?

Bouyoucos (1936) proposed a more rapid and simpler procedure called the hydrometer method. Both analytical techniques are sedimentation procedures accepted as standard techniques for particle-size analysis.