The soil was found to have the following water retention characteristics: Water content at -10 kPa (field
Question:
The soil was found to have the following water retention characteristics:
Water content at -10 kPa (field capacity) = 0.15 kg kg-1; water content at -1500 kPa (wilting point) = 0.06 kg kg-1. The bulk density was found to be 1250 kg m-3. Assume the density of water to be 1000 kg m-3.
1 Calculate the plant available water capacity (PAWC), expressing your results in in-depth units.
2 The crop growing in this field has a rooting depth of 40 cm. Calculate the plant available water (PAW) for this crop?
3 A farmer irrigated his soil to field capacity and then allowed it to dry out so that the PAW was 65% of its original value before he reapplied irrigation. Calculate the volume of water (per hectare of land) that the farmer must apply to raise the soil water content from the depletion level back to field capacity for the rooting depth of the crop.
An Introduction to Geotechnical Engineering
ISBN: 978-0132496346
2nd edition
Authors: Robert D. Holtz, William D. Kovacs, Thomas C. Sheahan