SWES 200 quiz 6 - kPa. Volumetric water content =...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
SWES 200 Introduction to Soil Science Quiz 6 A soil sample is weighed at a range of soil matric water potentials. The dry weight of the soil is 100g. The weights are shown in the table below. The bulk density of the soil is 1.3 g/cm . 3 Water potential (kPa) Weight (g) 0 135 -1 131 -10 127 -100 115 -1000 109 -1500 108 -10000 104 1. What are the gravimetric and volumetric water contents at Gravimetric (%) Volumetric (%) Saturation 35 % 45.5 % Field Capacity 27 % 35.1 % Permanent Wilting Percentage 8 % 10.4 % The soil is saturated with water when the matric potential = 0 kPa. It is at field capacity when matric potential = -10 to -30 kPa. is saturation and at permanent wilting percentage at -1500
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: kPa. Volumetric water content = gravimetric water content x bulk density. 2. How much plant available water does 1 ft of this soil hold? Plant available water = field capacity - permanent wilting percentage (using volumetric water contents): 35.1 - 10.4 = 24.7%. This means that 1 foot of soil holds 0.247 feet or 2.96 inches of available water. 3. What is the porosity of this soil (%)? The easy way to answer this is to say that, at saturation, all pores are filled with water, so the porosity of this soil is 45.5%. You can also calculate it based on the bulk density and the assumption that particle density is 2.65 g/cm . 3...
View Full Document

This test prep was uploaded on 04/03/2008 for the course SWES 200 taught by Professor Walworth during the Spring '08 term at University of Arizona- Tucson.

Ask a homework question - tutors are online