Question

Salinization occurs when the irrigation water accumulated in the soil evaporates, leaving behind salts and minerals. What are the effects of salinization on the irrigated land? 
1. It greatly increases the crop production.
2. It makes some soils impermeable.
3. It raises the water table.
4. It fills the air spaces in the soil with water.

Answer 1

Correct Answer - Option 2 : It makes some soils impermeable.

The correct answer is It makes some soils impermeable.

• Salinization:
  • Salinity is the presence of salts (such as sodium chloride, magnesium and calcium sulfates) and bicarbonates, in soil and water.
• Problems due to soil salinity:
  • Agricultural Production- Inefficient osmosis due to high salt concentration can result in dehydration of the plant, causing yield decline or even death of the plant. Salinity affects production in crops, pastures and trees by interfering with nitrogen uptake, reducing growth and stopping plant reproduction.
  • Water quality- High levels of salts may affect the taste of drinking water. Chloride in particular has a low taste threshold. Sodium and magnesium sulfate levels in drinking water may produce a laxative effect and reduce the suitability of a water supply for grazing animals.
  • Rivers- Salt interacts with in-stream biota (animals and plants), changing the ecological health of streams and estuaries. Salts also help fine materials (such as suspended clay particles) to flocculate, allowing more sunlight to penetrate rivers and leading to harmful algal blooms.
  • Terrestrial biodiversity- Salinization can lead to the destruction of the remaining natural habitat in many agricultural areas and the fragmentation of many wildlife corridors.
  • Soil erosion- Salinity is often associated with prolonged wetness and lack of surface cover and therefore increases the vulnerability of soils to erosion. It makes some soils impermeable.
  • Flood risk- Saline soils have a limited capacity to absorb rainfall, resulting in high rates of run-off. 
  • Infrastructure- Salt also corrodes and destroys the infrastructure including houses, roads and playing fields.