Soil water available to roots is

Correct option is D

Introduction
· Soil water is the water held in the soil pores, which is essential for transporting nutrients from the soil to the various parts of the plant.
· It is classified into different types based on the physical forces that hold the water molecules against the soil particles.
· The availability of this water to plants depends on the soil texture, structure, and the tension with which the water is retained.

Information Booster
· Capillary water is the correct answer because it is the only form of soil water that is actually available for plant root absorption.
· It is held in the micropores of the soil against the force of gravity by surface tension (capillary action).
· This water exists as a film around soil particles and is retained at a tension between field capacity (1/3 bar) and permanent wilting point (15 bars).
· Because it is held loosely enough for roots to overcome the tension but tightly enough not to drain away, it serves as the primary reservoir for plant growth.
· The amount of Capillary water is highest in loamy soils, which provide the best balance of aeration and water retention for agriculture.

Additional Knowledge
· Surface water refers to water that collects on the ground or in a stream, river, lake, or wetland; while it eventually infiltrates the soil, it is not a technical category of soil-stored water available to roots.
· Hygroscopic water is held very tightly by soil particles as a thin molecular film due to adhesive forces; it is held at such high tension (above 31 bars) that plant roots are physically unable to extract it.
· Gravitational water occupies the large macropores and drains away rapidly through the soil profile due to the force of gravity after heavy rain or irrigation, making it unavailable for long-term plant use.
· Field Capacity is the condition reached after Gravitational water has drained away, leaving only the Capillary water and Hygroscopic water in the soil profile.