Magnesium sulphate (MgSO4) can be used as a fertilizer to provide plants with essential magnesium and sulfur nutrients. These nutrients are important for the growth and development of plants and play a role in various metabolic processes, such as photosynthesis and protein synthesis. Magnesium sulfate fertilizer can be applied to soil through irrigation systems or directly to plant leaves as a foliar spray. The amount and timing of application depend on the crop and soil conditions. However, it is important to note that excessive application of magnesium sulfate can result in toxicity and damage to plants.