What is the difference between bulk density and particle density

Introduction to Soil Science. On Jul 31, Table Particle density of different soil textural classes Related Posts. More Stories. Soil Air Apr 6, Soil Colloids Mar 29, Soil Water Potential Mar 28, Prev Next 1 of Sign in. Welcome, Login to your account. Forget password? From the weight of soil and volume of cylinder, the bulk density of soil is calculated. This is the true field bulk density determined in an un-disturbed soil core.

Pin enters easily and neatly: 1 g cc-1 : soil is very loose A. Pore space - Definition of macro and micro pore space - Factors affecting pore space - Soil compactness - Internal surface area - Factors influencing. The pore space of a soil is the space occupied by air and water. The amount or ratio of pore space in a soil is determined by the arrangement of soil particles like sand, silt and clay.

In sandy soils, the particles are arranged closely and the pore space is low. In clay soils, the particles are arranged in popous aggregates and the pore space is high. Presence of organic matter increases the pore space. Virgin soils have more pore space. Continuous cropping reduces pore space than intermittent cropping.

More the number of crops per year, lesser will be the pore space particularly macro pores. Conservation tillage and no tillage reduces porosity than conventional tillage Size of pores 1.

In micro pores, the movement of air and water is very slow and restricted to capillary movement and diffusion. So in sandy soils, water and air movement is rapid due to macro pores though the pore space is higher and in clay soils the air and water is slower due to micro pores though the total pore space is higher.

Specific surface of soil particles The total surface area per unit volume of soil or per unit weight of soil is called specific surface and expressed as cm2 cm-3 or m2 g-1 soil Specific surface of soil is an important parameter as most physical and chemical reactions in soil depends on and occur on the surface of soil particles. Clay and silt are the most reactive parts of soil and hence their surface area is also important. The smaller the particle size, the higher will be the specific surface area and hence clay will have more specific surface area than sand.

Montmorillonite clay to m2 g-1 Illite clay 60 to m2 g-1 Kaolinite clay 20 to 40 m2 g-1 Clay soil to m2 g-1 Silty clay loam to m2 g-1 Loam 50 to m2 g-1 Sandy loam 10 to 40 m2 g-1 Silt soil 5 to 20 m2 g-1 A. Soil colour - Significance - Munsell colour chart-hue, value and chroma - Factors influencing soil colour. Colour is an optical phenomena perceived by our eyes. Human eyes can perceive the visible range of electro magnetic radiation EMR consisting of various colours ranging from red to blue.

Combination of all colours result in white light and absence of all colours is perceived as black. Colour of an object is due to absorption of certain wavelengths of the visible spectrum light and reflection of the others. The combination of different reflected wavelengths of the EMR produce different colours. Soil also absorbs certain wavelengths of the EMR and reflects the other. Soil colour is due to the reflection of EMR by different soil constituents like minerals, organic matter, water, salts, etc.

Generally organic matters absorb all the colours and so black in colour. Different minerals absorb different colours. Iron oxides reflect red, brown and yellow colours. Salts reflect all the colours and hence look white. Combination of these various colours composite gives the soil colour.

This is due to the presence of iron, manganese and copper in soil in patches. Measurement of soil colour Soil colour is measured using Munsell colour chart refer to practical manual for details and expressed in terms of Hue, Value and Chroma. These three parameters are called as soil colour notations or Munsell colour notations.

Hue denotes the Dominant spectral colour Value denotes the Intensity of colour Chroma denotes the Purity of colour These three parameters are expressed in the following format. Chroma Value Hue A. Organic matter is a very small portion of the solids, so it is usually ignored in this calculation.

The mineral solids would weigh 1. For practice, consider a box of undisturbed soil from the field. The box has dimensions of 2. The volume of the box can be determined by multiplying the height of the box times its width and its depth. The wet soil in the box weighed g. The dry soil weighed g. Bulk materials are substances such as powders, precipitates, crystals or even gelatin materials.

The basic property of bulk materials is that, the bulk materials have pockets of other materials such as air, water or even some other materials. The bulk density of a given substance greatly varies on the condition the material is in. A closely packed sample of a material would have a higher bulk density than a normally poured sample. This concept is very important in chemistry. Therefore, bulk densities are categorized into two, they are freely settled bulk density, also known as poured bulk density, which is taken without any disturbance to the poured material, and the tapped density, which is recorded after a certain procedure of packing the substance.

What is the difference between density and bulk density?