Explanation
Salinization refers to the accumulation of soluble salts in the soil resulting from irrigation practices where water evaporates, leaving salts behind. This process adversely affects soil structure and fertility.
Option (a) is incorrect: Salinization reduces crop yields as excess salts in the soil create osmotic stress on plants which hin-ders their ability to absorb water and nutrients. This leads to stunted growth and lower productivity.
Option (b) is correct: Salinization causes soil particles to disperse and clog pores which makes the soil impermeable. This is known as sodic soil degradation. This dispersion leads to the clogging of soil pores, reducing permeability and making the soil less capable of absorbing water. Thus water infiltration decreases and the soil becomes impermeable.
Option (c) is incorrect: Salinization generally occurs due to poor drainage but it does not necessarily raise the water table. On the contrary, a high water table can exacerbate salinization by bringing saline groundwater closer to the root zone through capillary action.
Option (d) is incorrect: Salinization does not directly fill air spaces in the soil with water. It can lead to waterlogging due to reduced soil permeability which indirectly affects soil aeration. Waterlogging displaces air from soil pores which deprives plant roots of oxygen.