What is field capacity?

• A. When macropores have drained and micropores still contain water
• B. Rate of water runoff from the field
• C. Soil moisture at saturation
• D. When micropores have drained and macropores contain water

Answer: (A)

Field capacity is the amount of water the soil holds after gravity drainage has occurred. When a soil is wetted and allowed to drain, the larger pores (macropores) drain quickly, while the smaller pores (micropores) retain water due to capillary forces. The remaining water content, after this drainage, is the field capacity. This moisture level reflects the soil’s ability to hold water that is potentially available to plants between rainfall events. It’s not the saturation point (all pores filled) and not a measure of runoff rate.