Soil water potential

Soil water potential is the energy state of water.

Potential of pure water is zero because pure water is not exerted any extra forces.

Soil water has negative water potential.

Water usually flows from less water potential to more water potential.

¥T= ¥g + ¥m + ¥o

¥t-Total water potential

¥g- Gravitational potential

¥m-Matric potential

¥o-Osmatric potential

¥o- Concentration difference of solutions which are separated by semi-membrane is causes for matric potential. The solution has high concentration means that the water potential of the solution is relatively low. The solution has low concentration means that the water potential of the solution is relatively high therefore water moves from solution which has a low concentration to the solution which has a high concentration. Water moves until occurring of equilibrium between both sides of the cell membrane.

Ym- Osmatric potential is the result of both capillary forces and adsorptive forces. The capillary force causes the formation of a gas-liquid interface. Adsorptive forces between soil and water surface are occurred due to the extension of wander Waals forces by the cohesive of hydrogen bonds between water molecules.

Yg-The force of gravity which is exerted from the vertical side is pulled from the water towards gravity.