AGRI20038 Principles of Soil Science
Task:
This assessment task is worth 20% and is based on the knowledge gained during the Practical 3 (Soil physics). You will need to perform calculations and present data for K and Ksat for a Ferrosol following Task 1 and 2 below, and answer questions as posed in Task
TASK 1 Disc permeameter for unsaturated hydraulic conductivity (K) (10%):
Using the dataset for the Red Ferrosol provided on the Canvas assignment site:
(a) For the -50 mm tension setting:
(i) Present a scatterplot chart of cumulative infiltration with time (hrs), and describe how the values change with time;
(ii) Present a table showing your selected ‘steady-state’ range of data points (≥ 5) for cumulative infiltration with time (hrs); and briefly explain the choice;
(iii) Present an Excel scatterplot chart of the selected steady-state data points, fit a trend line, add the equation of the line and corresponding R2 value.
(iv) report the K value at -50 mm
(b) For the -20 mm tension setting:
(i) Present a scatterplot chart of cumulative infiltration with time (hrs), and describe how the values change with time;
(ii) Present a table showing your selected ‘steady-state’ range of data points (≥ 5) for cumulative infiltration with time (hrs); and briefly explain the choice;
(iii) Present an Excel scatterplot chart of the selected steady-state data points, fit a trend line, add the equation of the line and corresponding R2 value.
(iv) report the K value at -20 mm
(c) Explain the reasons for any observed differences in K between the -50 mm and -20 mm settings
