discussion session no 1 (group six)
Two soil samples with similar textures are placed in close contact. one has matric potential of -1m, the other -0.01m. Which soil likely has the higher water content? In which direction will water move and why.
I am thinking that the second sample with a matric potential of -0.01 has higher water content and I know the water will move in the direction from wet to dry. But I dont know how to explain myself. help
At saturation, matric potential = 0 As the soil dries, large pores will empty 1st, water is held within small pores (by capillary) and on thin water films around soil colloids (by adhesion). The drier the soil, the smaller matric potential (i.e. larger –ve); the tighter the soil water is held (higher tension), the lower freedom of movement. Therefore: the soil with the higher matric potential (smaller –ve) in this example – 0,01 m will have the higher water content.