Question

In the winter, grass often dies near roads that have been salted to remove ice. Explain what causes the death of the grass.

Answer 1

The death of grass near salted roads in winter is primarily due to osmotic stress caused by increased salt concentration in the soil, leading to plant dehydration and eventual soil salinization.

Step-by-step explanation:

In regions where winter conditions are prevalent, the application of deicing salts such as sodium chloride (NaCl) or calcium chloride (CaCl₂) on roads is a common measure to prevent ice formation and ensure safer travel. While effective for deicing, these salts can adversely affect nearby vegetation. When salt is spread on roads to melt ice, it can dissolve and spread into the surrounding soil. The phenomenon that leads to the death of grass near salted roads is due to a process called osmotic stress, which is caused by the increase in salt concentration in the soil near the roads.

As the salt concentration in the soil increases, it creates a situation where the water potential outside the plant roots is lower than inside. This causes water to move out of the plant's cells to balance the concentration, leading to dehydration of the grass. Over time, the constant exposure to high salt levels can lead to salinization of the soil, meaning that the soil contains high levels of salt which makes it less productive and can ultimately result in the death of many plants, including grass.