Field capacity is defined as the water content after gravitational drainage.

• A. Capillary rise only
• B. Saturation water content
• C. Moisture content at the permanent wilting point
• D. Water content after gravitational drainage

Answer: (D)

Field capacity is the amount of water left in soil after gravity has drained the excess freely draining water. When soil is allowed to drain, water moves out of larger pores under gravity, and the remaining water is held by capillary and matric forces at a low suction. This residual water content is what plants can access under typical conditions, but it is not the water that remains when all pores are full (saturation), nor the much drier moisture level at the permanent wilting point, and it is not the upward movement of water due to capillary rise. Therefore the best description is the water content after gravitational drainage.