Download - Soil water energy concept
Group C4
Due to gravitational forces
According to concentration gradient
Water moves from high water potential to low water potential
Wet soil to dry soil
Wet soil
◦ High amount of pore space
◦ High water potential
Dry soil
◦ Low amount of pore space
◦ Low water potential
Gravimetric potential◦ Helps water to move by gravity
Pressure potential◦ Submerged potential
◦ Matrix potential
Osmotic potential◦ Moves water according to the dissolving of particles
Capillary force◦ Adhesion and cohesion
Adsorptive forces
Osmotic forces
Capillary force
◦Due to adhesive and cohesive powers
Adhesion
Tendency of dissimilar particles or surfaces to cling to one another
Cohesion
Tendency of similar or identical particles to cling to one another
◦Due to properties of water, it moves through the soil
◦ Small pores in the soil can be assumed as capillary tubes
◦ r α 1/h
◦ Large pore space – low water movement
◦ Small pore space – high water movement
Water binds strongly to mineral surfaces due to polarity in molecules
This results in forming a thin water film
Water moving between roots and soil
Through the cell membranes of root hairs, which are semi permiable
According to a water potential gradient
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