Question

A farmer’s field gets flooded due to lack of proper drainage, which results in waterlogging. He gradually sees a reduction in yield with plants showing stunted and uneven growth. What might be the probable cause of this?

• A. Soil erosion
• B. Mineral deficiency
• C. Increase in soil salinity
• D. Decrease in soil salinity

Answer 1

The correct option is C Increase in soil salinity

While farming, irrigation is a very important and crucial step for the growth of crops. Irrigation without proper drainage of water leads to waterlogging in the soil.

Waterlogging damages the crops and also draws salt to the surface of the soil. Over time, excess water in the field evaporates leaving behind the salt dissolved in it. This salt then deposits as a thin crust over the land. It is this salt deposition that increases soil salinity. This increased salt content is inimical (not favourable) to the growth of crops and is extremely damaging to agriculture.

Excess soil salinity causes poor and spotty stands of crops, uneven and stunted growth and poor yields, the extent of which depends on the degree of salinity.

The primary effect of excess salinity is that it renders less water available to plants. This is because the osmotic pressure of the soil solution increases as the salt concentration increases. Apart from the osmotic effect of salts in the soil solution, excessive concentration and absorption of individual ions may prove toxic to the plants and/or may retard the absorption of other essential plant nutrients. Crop yields reduce markedly before visual symptoms of salinity damage become apparent.

Mineral deficiency can also cause stunted growth in plants but in the given scenario, the stunted plant growth is due to an increase in the soil salinity.

Removal of top fertile soil is called soil erosion. Activities resulting in soil erosion are like over-cultivation, unrestricted grazing, deforestation, etc.