Which of the following is a common soil conditioner used to improve soil structure?

Vermiculite is a common soil conditioner recognized for its ability to improve soil structure significantly. It is a mineral that, upon heating, expands and becomes lightweight, enhancing the soil's aeration and moisture retention capabilities. By incorporating vermiculite into soil, it helps to create a more favorable environment for plant roots, promoting healthier growth.

Moreover, vermiculite contributes to improved drainage and facilitates better root penetration, which is essential for plant health. Its structure allows for better retention of nutrients, making them more available to plants. This improvement in soil structure leads to enhanced soil health overall.

In contrast, fertilizers primarily supply nutrients rather than improving soil structure, while herbicides are designed to control unwanted plants and do not enhance soil properties. Water, although essential for life and influencing soil moisture, does not change the physical composition or texture of the soil in a way that conditioners like vermiculite do. Understanding the distinct roles of these materials is critical for effective soil management in gardening and agriculture.