• Statement (I) is true: In strongly acidic soils, exchange sites are predominantly occupied by toxic aluminum ($Al^{3+}$) and hydrogen ($H^+$), resulting in low effective CEC and high leaching of potassium ($K^+$). Liming increases soil pH, neutralizes exchangeable $Al^{3+}$, and generates pH-dependent negative charges (CEC), allowing more $K^+$ to be retained on the exchange complex against leaching.
• Statement (II) is true: In soils already at near-neutral pH (6.0–7.5), excessive liming floods the soil solution with calcium ($Ca^{2+}$) ions, causing strong Ca-K ionic antagonism at root carrier channels ("lime-induced potassium deficiency") and can lower the relative exchangeable K saturation.
• Conclusion: Both Statement (I) and Statement (II) are true. (Correct answer: Option 1)

• Question Status: Dropped by NTA.
• Technical Analysis: Sodium nitrate ($NaNO_3$) is a basic-forming fertilizer with an equivalent basicity of ~29, meaning its prolonged application increases (not decreases) soil pH and leads to soil sodication. Therefore, statement (C) is false.
• Statements (A), (B), and (D): Nitrate salts of sodium and potassium are non-acid-forming; calcium nitrate ($Ca(NO_3)_2$) is highly preferred for winter vegetables due to immediate nitrate availability and calcium nutrition in cold soils. Because the correct combination "(A), (B), and (D) only" was missing from the given options, the question was officially dropped. (Correct answer: Dropped)

• Step 1: Calculate Total Nitrogen Applied:

$$\text{Urea Applied} = 220\text{ kg/ha}$$ $$\text{N content of Urea} = 46\%$$ $$\text{Nitrogen Applied (N)} = 220 \times 0.46 = 101.2\text{ kg N/ha}$$

• Step 2: Calculate Yield Increase over Control:

$$\text{Yield in Fertilized Plot } (Y_f) = 6\text{ t/ha} = 6,000\text{ kg/ha}$$ $$\text{Yield in Control Plot } (Y_0) = 3\text{ t/ha} = 3,000\text{ kg/ha}$$ $$\Delta Y = 6,000 - 3,000 = 3,000\text{ kg/ha}$$

• Step 3: Calculate Agronomic Efficiency ($AE_N$):

$$AE_N = \frac{Y_f - Y_0}{\text{N applied}} = \frac{3,000\text{ kg grain}}{101.2\text{ kg N}} \approx 29.64\text{ kg grain / kg N applied}$$

• Conclusion: Agronomic efficiency is 29.6 kg grain / kg N applied. (Correct answer: Option 4)

• Step 1: Calculate Phosphorus in Fresh FYM:

$$\text{Dry matter in fresh FYM} = 100\% - 60\% = 40\% = 0.40\text{ kg dry/kg fresh}$$ $$\text{P content in dry FYM} = 0.2\% = 0.002\text{ kg P/kg dry}$$ $$\text{P content per kg fresh FYM} = 0.40 \times 0.002 = 0.0008\text{ kg P/kg fresh FYM}$$

• Step 2: Calculate Cost per kg of P ($P_x$):

$$P_x = \frac{\text{Cost per kg fresh FYM}}{\text{kg P per kg fresh FYM}} = \frac{\text{Rs } 2.64}{0.0008\text{ kg P}} = \text{Rs } 3,300\text{ per kg P}$$

• Step 3: Calculate Price of Pigeonpea per Tonne ($P_y$):

$$\text{Price per quintal} = \text{Rs } 6,600 \implies \text{Price per tonne } (10\text{ quintals}) = 6,600 \times 10 = \text{Rs } 66,000\text{ per tonne}$$

• Step 4: Calculate Economic Price Ratio ($\frac{P_x}{P_y}$):

$$\text{Price Ratio} = \frac{P_x}{P_y} = \frac{3,300}{66,000} = 0.05$$

• Conclusion: The price ratio for estimating the economic optimum P application is 0.05. (Correct answer: Option 4)