Which one of the following statements is not correct?

Which one of the following statements is not correct?

Application of lime makes the soil acidic.
High acidity in soil is typical of humid climate.
Increasing soil acidity results in declining soil fertility.
Arid climate is characterized by alkaline soil.
This question was previously asked in
UPSC NDA-2 – 2015
Let’s analyze each statement about soil acidity:
A) Application of lime (usually calcium carbonate, CaCO₃, or calcium oxide, CaO, which reacts with water to form calcium hydroxide, Ca(OH)₂) is a common agricultural practice used to *reduce* soil acidity and increase pH, making the soil more alkaline or neutral. Therefore, applying lime does not make the soil acidic; it makes it less acidic. This statement is not correct.
Lime is applied to soil to neutralize acidity (increase pH), not to make it acidic.
B) High acidity in soil is typical of humid climates where high rainfall leads to leaching of basic cations (Ca²⁺, Mg²⁺, K⁺, Na⁺) from the topsoil, leaving behind acidic ions like H⁺ and Al³⁺.
C) Increasing soil acidity can lead to declining soil fertility because essential plant nutrients (like phosphorus) become less available, and potentially toxic elements (like aluminum and manganese) become more soluble and available at low pH levels.
D) Arid climates are characterized by low rainfall, which limits the leaching of basic cations. Evaporation can also bring dissolved salts to the surface, often resulting in the accumulation of carbonates and other salts that contribute to alkalinity. Hence, arid soils are often alkaline or saline.
Since the question asks for the statement that is *not* correct, option A is the answer.