Improved method of making soil monoliths using an acrylic bonding agent and proline auger

Abstract

This soil monolith production method, initially developed in the late 1990s, has now been successfully applied to over 100 soil profiles, dealing with the majority of Australian soils ranging from clays to sands, from uniform to texture contrast profiles, and from alkaline soils to even acid sulphate soils. The method outlined utilises intact soil profiles (150 mm diameter undisturbed soil cores collected with a Proline hollow flight auger). This technique is rapid and minimises site disturbance. A modern acrylic bonding compound (Bondcryl 737 ®) was selected as the bonding agent because it is strong, durable, UV resistant, and non-toxic. The bonding agent is applied to the soil profile as a series of fine misty sprays using a hand pump action spray bottle. After several applications the solution permeates through the outer 5 mm or more of the soil, bonding the whole profile together. The finished soil monolith has a moist soil colour, but with a natural non-glossy appearance. A decade has now passed since the first monoliths were made using this method, and those monoliths are still being transported and displayed regularly. They remain in good condition, giving us some confidence in the reliability of this method.