Read carefully below mentioned statements: (A). Organisms with... | Agrigyan

• Classical Potassium Concepts and Theories in Soil Science:
• P.H.T. Beckett (1964): Formulated the thermodynamic Quantity-Intensity ($Q/I$) relationship of soil potassium $\rightarrow$ (II)
• O.F. Haylock (1956): Formulated the empirical extraction concepts of "Step-K" and "Constant Rate-K" for estimating non-exchangeable reserve potassium $\rightarrow$ (I)
• J.B. Page and L.D. Baver (1940): Proposed the Lattice Hole Theory explaining that $ ext{K}^+$ ($r = 1.33\text{ Å}$) fits precisely into ditrigonal cavities of hexagonal oxygen rings in 2:1 clay layers, causing fixation $\rightarrow$ (IV)
• F.G. Viets (1944): Discovered the "Viets Effect", showing that moderate external $ ext{Ca}^{2+}$ concentrations enhance root uptake of monovalent cations ($ ext{K}^+$) $\rightarrow$ (III)
• Systematic Match: (A)-(II), (B)-(I), (C)-(IV), (D)-(III) corresponds to Option 3.

Correct option: (3) (A) - (II), (B) - (1), (C) - (IV), (D) - (HH)

• Quantitative Volumetric Analysis Titrations and Chemical Indicators:
• Precipitation Titration: Uses Potassium chromate ($ ext{K}_2 ext{CrO}_4$) in Mohr's method (forming red $ ext{Ag}_2 ext{CrO}_4$) or Ferric alum in Volhard's method $\rightarrow$ (IV)
• Neutralization (Acid-Base) Titration: Uses pH indicators such as Thymolphthalein and Bromophenol blue $\rightarrow$ (III)
• Adsorption Indicator Titration (Fajans Method): Uses anionic dye indicators such as Fluorescein and Eosin that adsorb at the isoelectric equivalence point $\rightarrow$ (I)
• Oxidation-Reduction (Redox) Titration: Uses redox indicators such as Ferroin (1,10-phenanthroline iron(II)) and Diphenylamine $\rightarrow$ (II)
• Systematic Match: (A)-(IV), (B)-(III), (C)-(I), (D)-(II) corresponds to Option 4.

Correct option: (4) (A) - (IV), (B) - (MN), (C)~ (), (B) - (HN)

• Statement (A) is correct: In alkaline or over-limed soils ($pH \gt 6.8$), phosphorus precipitates into insoluble dicalcium or tricalcium phosphates, reducing plant P availability.
• Statement (B) is correct: Increasing soil pH decreases the solubility and bioavailability of Fe, Mn, Zn, Cu, and B; only molybdenum ($Mo$) availability increases with liming.
• Statement (C) is correct: Calcium ($Ca^{2+}$) replaces monovalent cations on clay edges, promoting flocculation and stabilizing aggregate crumb structure.
• Statement (D) is incorrect: Common potato scab caused by Streptomyces scabies is favored by neutral to alkaline soil ($pH \gt 5.2$); liming strongly increases (rather than decreases) scab disease incidence.
• Conclusion: Statements (A), (B), and (C) only are correct. (Correct answer: Option 1)