Soil: A Media for Plant Growth
The role of soil in the soil–plant–atmosphere Continuum is unique. Although soil is not essential for plant growth and indeed plants can be grown hydroponically (in a liquid culture), usually plants are grown in the soil, and soil properties directly affect the availability of water and nutrients to plants. Soil water affects plant growth directly through its controlling effect on plant water status and indirectly through its effect on aeration, temperature, nutrient transport, uptake, and transformation. The knowledge of soil-water status and its movement in soil is important and has practical implications in agricultural, environmental, and hydrological situations. Soil-water movement in the field depends on the hydraulic properties of the soil. The understanding of these properties is helpful in good irrigation design and management.