ICAR AIEEA PG Entomology 09 July 2023 (Shift 1) Paper

Historical pioneers in soil science:

• Emil Truog (written as M. L. Trong in NTA question paper): Renowned soil chemist at the University of Wisconsin who pioneered quick chemical soil testing methods, developed the Truog method for available phosphorus determination, and is widely acknowledged as the father of modern soil testing.
• James Stuart: Pioneer of agricultural extension in England (1867).
• S. N. Winogradsky: Father of soil microbiology (discovered chemoautotrophy and nitrifying bacteria).
• Geoffrey Milne: Proposed the 'Catena' concept in soil toposequence (1935).

Statistical classification of data parameters:

• Range: The absolute simplest and quickest measure of dispersion or variability, calculated straightforwardly as $\text{Range} = X_{\text{max}} - X_{\text{min}}$.
• Mean: Measure of central tendency (arithmetic average), not a measure of variability.
• Mode: Measure of central tendency (most frequent observation).
• Median: Positional measure of central tendency.

Standard analytical protocols in soil chemistry:

• Total nitrogen: Determined using the macro/micro Kjeldahl digestion and distillation method -> (IV).
• Available nitrogen: Determined by the Subbiah and Asija alkaline potassium permanganate ($\text{KMnO}_4$) distillation method -> (II).
• Potassium (K): Determined by neutral normal ammonium acetate extraction using a Flame Photometer -> (I).
• Available sulphate sulphur ($\text{SO}_4^{2-}$): Determined using the Chesnin and Yien barium chloride turbidimetric/turbidimetric method -> (III).