Fieldwork Techniques  5 of 7 Pages Profile Survey Insert a ranging rod at the start of your survey line and insert a second rod 25 metres away and a third a further 25 metres away. Measure the bearing from the first to the second rod. N.B. Keep this line as far as possible. Measure the angle of slope between ranging rods 1 and 2, and 2 and 3. Record these values in a table. Measure the soil depth, soil type and pH at each of the ranging rods and record the values the table. Continue down the slope measuring the angle of slope, soil depth, soil type and pH every 25 metres. Students measuring slope profile in the French Alps Students measuring slope angle in North Wales Soil Depth Using an auger, twist it into the soil until you either hit bed-rock, unconsolidated rock fragments or run out of auger. Record the depth of the soil, indicate if the soil is deeper than the auger's length. Students measuring soil depth and collecting samples in North Wales Field Measurement of Soil pH Place a volume of soil, taken from just below the surface vegetation, into a container. Add an equal volume of distilled water. Shake the soil intermittently for 5 minutes. Use a field pH meter to record the soil's pH. Clean the pH meter and switch it off when you finish!! N.B. Soil pH is an extremely important soil parameter as it governs the presence and availability of nutrient ions for plant uptake, and similarly affects the behaviour of toxic elements in soils. Soil pH is dependent on the proportion of clay, silt, sand and organic matter present in the soil. Drawing a Slope Profile Plot to scale your transect to show the soil depth vs. distance. You will need a ruler, graph paper, protractor, rubber, calculator. Since your line is ~200 metres long, select a scale which will allow you to represent the full line. e.g. 1cm to 10m. Draw on the horizontal scale axis and the vertical axis. Starting at sample point 1, start to plot each segment of the line (see below). Plot to scale the soil depth at each sample point. When you have plotted all the sections and soil depths, join up the lines to show the soil profile and the soil-rock boundary. Give your section a title, label the axes and insert any labels and key you think appropriate. Example of how to plot the transect y = measured slope distance 0 = slope angle x = horizontal distance between sites h = height between each sample site Start at site 1, and using a protractor, plot the slope angle from the x-axis towards the y-axis. Start at site 1, plot the measured slope distance (to scale) - draw a line to scale parallel to the slope angle. Vertically down from end of this line will be site 2. Repeat for all site numbers. You can also plot the transect by using trigonometry to calculate the x and h values for each triangle between sample sites. Soil / Slope Relationships Some soil and slope relationshipe that you may consider include:- soil depth vs. angle of slope pH vs. angle of slope soil depth vs. distance down slope pH vs. distance down slope | 1 | 2 | 3 | 4 | 5 | 6 | 7 | Page 5 of 7