Be consistent in the proportions used. Use pH strips to determine the pH of the solution. This a not true measure of the soil's pH, but it is useful for relative values. Since the pH scale is a log scale, the answer won't be too far off. This might be a good opportunity to discuss the nature of a log scale and exponents.
Most soil nutrients are cations.
Soil Type Soil is classified using a triangle which has sand at one point, loam at another, and clay at another. A sample might fall anywhere in that triangle. One way to get it is by measuring along two adjacent sides of an area and choosing random numbers from a random number table to get coordinates for a starting point. Another method is throwing a plastic disk with a line marked on it to get a direction, then using a random number table to get a travel distance in that direction. Linear transects Transects are lines with sampling points at regular distances.