Which is the particle size of clay soil?

Correct option is C

The correct answer is (C) 0.001 – 0.002 mm

Explanation:
• Soil texture is determined by the proportion of three types of particles: sand, silt, and clay.
• According to the International Society of Soil Science (ISSS) and the USDA, clay is defined as soil particles with a diameter of less than 0.002 mm.
• Therefore, the range 0.001 – 0.002 mm falls within the definition of clay.
• Clay particles are so small that they can only be seen with an electron microscope. They have a high surface area-to-volume ratio, which gives them unique chemical properties like high Cation Exchange Capacity (CEC).

Information Booster:
• Clay soil has high water-holding capacity but poor drainage and aeration compared to sandy soil.

Additional Knowledge:
• Sand (Option D): Usually defined as particles between 0.05 mm and 2.0 mm (USDA) or 0.2 mm to 2.0 mm (ISSS).
• Silt (Option B): Particles between 0.002 mm and 0.02 mm (ISSS) or 0.002 mm to 0.05 mm (USDA).
• Loam: Not a single particle size, but a balanced mixture of sand, silt, and clay.