3.4 Problem Set
- A cylindrical soil sample of 3.85 cm diameter and 10.00 cm height weights 201.13 g. The sample is then oven dried at 105°C for 48 hours, reaching a final weight of 177.75 g. Assume a particle density of 2.65 g cm-3 and density of water 1.00 g cm-3. Calculate the sample’s:
- bulk density
- porosity
- gravimetric and volumetric water contents
- soil water storage in mm
- Calculate the soil water storage in mm for a 60 cm deep soil profile in which the A horizon is 25 cm thick and has a volumetric water content of 0.25 cm3 cm-3 and the B horizon is 35 cm thick and has a volumetric water content of 0.35 cm3 cm-3.
- Determine the correct value for x in the simplified capillary rise equation below using Eq. 3-2 and assuming a contact angle of 20°. For water, assume a surface tension of 7.3 x 10-2 N m-1 (1 N m-1 = 1 kg s-2) and density of 998 kg m-3.
- Use the result from the prior question to calculate the height of capillary rise in a 0.010 mm diameter capillary tube.
- Use the Campbell water retention function and data from Table 3-2 to find the volumetric water content of a sand and a clay loam at -10. kPa and -1500. kPa.