Dominance of quartz in soil coarse fractions:

• Quartz (crystalline silicon dioxide, $\text{SiO}_2$) is chemically inert, lacks cleavage planes, and possesses exceptional hardness (Mohs hardness 7).
• Due to its extreme resistance to physical and chemical weathering, quartz accumulates residually and constitutes $70-90\%$ of the sand and silt fractions in soils globally.

Pioneering role of J. W. Leather in India:

• Dr. J. Walter Leather was appointed as the first Imperial Agricultural Chemist to the Government of India in 1892.
• He pioneered the scientific classification of Indian soils, conducted landmark studies on water requirements of crops, drainage, and ushar (saline-alkali) soil reclamation at Dehra Dun and Pusa, earning the title of Father of Agricultural Chemistry and Soil Science in India.