In the coarse-textured soils of Michigan and the Upper Midwest, 95% of herbaceous plant roots are in
Question:
In the coarse-textured soils of Michigan and the Upper Midwest, 95% of herbaceous plant roots are in the top 120 cm of soil. In planning for a new herb farm, your employer has asked you to gather data needed to estimate the plant-available water-holding capacity of the farm's soil to a depth of 1.2 m. Here are the data you have assembled, based on averaging five relatively undisturbed soil cores per measurement:
Soil bulk density | Gravimetric water content at the indicated soil water potentials (kg water/kg soil) | |||||
Horizon | Soil depth (cm) | (g/cm3) | -25 kPa | -100 kPa | -1500 kPa | Air-dry |
Ap | from 0 to 34 | 1.26 | 0.152 | 0.136 | 0.040 | 0.021 |
E | from 34 to 57 | 1.60 | 0.140 | 0.099 | 0.023 | 0.017 |
Bhs | from 57 to 90 | 1.59 | 0.216 | 0.177 | 0.095 | 0.050 |
C | from 90 to 120 | 1.44 | 0.110 | 0.089 | 0.046 | 0.015 |
If these three soil horizons are relatively uniform and these samples are representative, then please estimate how many cm of plant-available water are held in this soil to a depth of 1.2 m (that is, if the total volume of plant-available water in the three horizons were converted to an equivalent depth of free water). Hint: Think of a column of soil 1 cm2 by 120 cm deep, but each soil horizon must be calculated separately and then summed.
Financial Management for Public Health and Not for Profit Organizations
ISBN: 978-0132805667
4th edition
Authors: Steven A. Finkler, Thad Calabrese