Question

Field capacity of the soil includes

• A. capillary and gravitational water
• B. capillary and runaway water
• C. hygroscopic and capillary water
• D. hygroscopic, capillary and bound water.

Answer 1

Answer: (D)

hygroscopic, capillary and bound water.

Answer 2

The optimum or maximum amount of water retained per unit dry weight of soil after. the stoppage of gravitational flow is called field capacity. It is 25-35% in common loam soil.The total water content present in the soil is called holard. The water available to plants is chresard (growth water = available water). It consists of roughly 75% of capillary water.The rest of soil water (hygroscopic, combined, water vapour and 25% of capillary water) is calledechard or unavailable water. Hygroscopic water occurs as a thin film on the soil particles and is not available to plants, while combined water is chemically bound with soil materials. Capillary water is present in microspores of soil having diameter of 20 urn or below and is available to plant mots for absorption