Question

the surface, it evaporates, leaving the salt ions behind. The map on the right shows the locations of saline soil problems in Eastern North Dakota. Beach and interbeach sand and sits Red River Saline soils Till lay and silt shale Dakota Paleozoic bedrock severe problem area Frequent inclusion in productive land .0ccsi nal inclusi ninputeland Rare inclusion in productive land Figure 4. The geologic cross section of Grand Forks County shows the re tions between the Dakota sandstone and the overlying giacial deposits. (After Benz et al, 1961)

Answer 1

Saline soils indicate that the soil contains high levels of salt.

Water potential is given by the equation, Ψ_w= Ψ_s + Ψ_p,

where Ψ_w is the water potential, Ψ_s is the solute potential, Ψ_p is the pressure potential.

Saline soils contains high solute concentration. Ψ_s decreases with increase in solute concentration.

A decrease in Ψ_s results in decreased Ψ_{w .}

(usually, plant contains negative Ψ_w , so that water moves from soil into plant)

Even the plant contains a negative Ψ_w . water movement occurs positive Ψ_w to negative Ψ_w (or from negative to more negative water potential).

However, in saline soils, Ψ_w is negative in both soil and water. Hence, there would be no water movement or a little water moves based on the negativity of water potential. Therefore, the plant becomes water deficient.

The same water deficiency occurs even in dry conditions.

Hence, the symptoms are similar in both the cases.