Question

What is leaching?

Answer 1

Hint: Leaching is a term used in agriculture which means loss of water soluble plant nutrients from the soil which is caused due to rain and irrigation. Leaching is an environmental concern when it contributes to groundwater contamination.

Complete answer:
Leaching depletes the nutrient rich soil in the field which makes the soil poor in nutrient content for cultivation of crops. Soil structure, application and type of fertilizers along with other factors are taken into account to avoid excessive nutrient loss. Drainage is also very important in the field to eliminate the excess amount of water present in the field. Leaching contaminates the ground water as it carries dissolved chemicals into the underground water supply. This causes the groundwater unfit for drinking purposes as it carries various chemicals which are mixed into water.

The chemicals which are dumped into groundwater through leaching adversely affect oxygen levels for both humans and aquatic animals. This human health issue caused due to contamination in water includes methemoglobinemia and anoxia which are commonly referred to as blue baby syndrome. The two types of leaching that mostly occur are nitrogen leaching and phosphorus leaching. Nitrogen is a major nutrient present in the fertilizers and it adds in groundwater as the fertilizers dissolve with the rain or irrigation water and leach down into ground water which pollutes it.

Note: Eutrophication, which is a decline in oxygen content of water and for aquatic systems which causes death of aquatic organisms and various marine species. Leaching also decreases the productivity of soil which causes more addition of fertilizers in the soil.