Why is ocean water not usable for drinking and crop irrigation?

Ocean water contains high concentrations of dissolved salts, predominantly sodium chloride (common salt). While humans and plants require essential minerals, the salt content in seawater is significantly higher than what is suitable for consumption or irrigation.

Drinking Seawater:

- Dehydration: Consuming seawater can actually worsen dehydration due to the high salt concentration. The kidneys must work harder to excrete the excess salt, leading to a net loss of water from the body.

- Electrolyte imbalance: The elevated salt content can disrupt the delicate balance of electrolytes in the body, potentially leading to health issues such as muscle cramps, nausea, and confusion.

Crop Irrigation:

- Salt accumulation: When seawater is used for irrigation, the salt concentration gradually builds up in the soil, making it less fertile and less conducive to plant growth. This phenomenon is known as salinization.

- Nutrient deficiency: Seawater lacks essential nutrients that plants need for proper growth and development. While seawater does contain some nutrients, such as nitrogen and phosphorus, their concentrations are insufficient for optimal plant growth.

- Reduced water uptake: High salt concentrations in the soil can reduce water uptake by plants. This can lead to water stress, stunted growth, and decreased crop yields.

To make ocean water usable for drinking and crop irrigation, it needs to undergo a desalination process to remove excess salt and other impurities. Desalination plants utilize advanced technologies, such as reverse osmosis and distillation, to produce freshwater from seawater. However, these processes are energy-intensive and can be costly, making desalinated water a comparatively more expensive source of freshwater compared to traditional sources like freshwater lakes, rivers, and groundwater.