1. Soil Water Balance Reading: Applied Hydrology Sections 4.1 and 4.2
Topics
Soil water properties
Soil water flux
Soil water balance
Quotation for today (from Socrates) "There is only one good, that is knowledge; there is only one evil, that is ignorance." Contributed by Matt Harold.

2. Table 1. Size limits (diameter in millimeters) of soil separates in the USDA soil textural classification system.
Soil Particle Sizes
Name of soil separate
Diameter limits (mm)
Very coarse sand*
Coarse sand
Medium sand
Fine sand
Very fine sand
Silt
Clay
less than 0.002

3. Soil Texture Triangle
Source: USDA Soil
Survey Manual Chapter 3

4. Soil Water Content
Soil Water Content

5. Soil Water Flux, q
q = Q/A

6. Energy fluxes at Freeman Ranch

7. Evaporation (mm/day)
Average = 1.1 mm/day
Average = 3.1 mm/day

9. Soil Water Content

10. Soil Water Balance at Freeman RanchP E
0 cm
Net Exchange
10 cm
20 cm

12. Soil Water Tension, y Measures the suction head of the soil water
Like p/g in fluid mechanics but its always a suction (negative head)
Three key variables in soil water movement
Flux, q
Water content, q
Tension, y