Which of the following substances must be present in the soil for growth of a healthy green plant?
Answer Details
Magnesium ions must be present in the soil for the growth of a healthy green plant. Magnesium is an essential mineral nutrient for plants and is involved in many important plant functions, such as photosynthesis, enzyme activation, and the production of chlorophyll. Chlorophyll is the pigment responsible for the green color of leaves and is necessary for photosynthesis. Without magnesium, plants cannot produce enough chlorophyll, which can result in yellowing leaves, stunted growth, and poor yields. While the other options listed are important for plant growth, magnesium ions are particularly crucial for a healthy green plant.