Importance of bulk density, particle density and porosity:

• They reflect the soil’s ability to function for structural support, water and solute movement, and soil aeration.
• They are also used to convert between weight and volume of soil.
• They are used to express soil physical, chemical and biological measurements on a volumetric basis for soil quality assessment and comparisons between management systems. This increases the validity of comparisons by removing error associated with differences in soil density at time of sampling.
• They show quality of soil for agriculture.
• They help to know evolutionary history of soil.
• By knowing this we can improve soil structure for agriculture.