Root is one of the vital organs of plants. It grows in the soil, and its function is absorbing nutrient and water from the soil, and then transporting them to plant parts above the earth's surface. So root plays an important role in the process of the growth of plants. In addition, root can make the fastest response to soil environment, and its growth is not only affected by soil properties, but also indirectly affected by the atmospheric environment. So, on forestry, agriculture and ecology, etc, studying ...