The upcoming discussion will update you about the differences between Diffusion Pressure Deficit and Water Potential.
Difference # Diffusion Pressure Deficit:
1. It is an old term coined by Meyer (1938) which is synonym with water potential.
2. It has positive value, e.g., 5 atm.
3. Diffusion pressure deficit is the reduction in diffusion pressure of solvent in a system over its pure state.
4. Water is absorbed by a system having higher DPD from another system with lower DPD.
5. DPD = OP – TP where all the terms are with positive values.
6. Matric pressure or imbibition force is not. considered.
Difference # Water Potential:
1. It is modern term coined by Slatyer and Taylor (1960) which is equivalent to DPD.
2. It has a negative value e.g.. -5 atm.
3. Water potential is reduction in free energy of solvent in a system over its pure state.
4. Water is absorbed by a system with lower Ѱw from another system with higher Ѱw .
5. Ѱw = Ѱs + Ѱp where Ѱs has a negative value while Ѱp has a positive value.
6. Matric potential or Ѱm is considered wherever it is appreciable.