SFI - SOIL WATER 1

Soil Water (Soil Moisture)

Water present in the soil pore spaces in both liquid (solution) and vapor forms, occupying approximately 25% of total soil volume in an ideal soil composition.

Nutritional Role

Functions as the primary medium for plant nutrition because essential soil nutrients must dissolve in water to be absorbed by roots.

Polarity of Water

The asymmetrical arrangement of hydrogen and oxygen atoms producing a partial negative charge near oxygen and partial positive charges near hydrogen, forming a dipole.

Hydrogen Bonding

Intermolecular electrostatic attraction linking adjacent water molecules together, accounting for high boiling points, high specific heat, and cohesive forces.

Cohesion

The attractive force binding water molecules to other water molecules.

Adhesion

The attractive force binding water molecules to solid surfaces, such as soil particle faces or plant cell walls.

Surface Tension

The inward cohesive pull exerted on water molecules at an air-water boundary, causing the liquid surface to contract and act like an elastic membrane.

Capillary Rise Equation

The relationship describing the height to which water ascends spontaneously in a narrow pore: h = 0.15/r ;

Interpretation: Height of rise (h) is inversely proportional to pore radius (r); smaller micropores pull water to significantly higher elevations than wide macropores.