199-14 Using Soil Material Identification to Rehabilitate Coalbed Methane Water Storage Ponds.
All the ponds were originally constructed by pushing up four walls of soil from a central point. This construction technique tends to invert the soil profile as the walls are built, often leaving hostile subsoil as the surface layer and preventing pasture establishment on the pond bank. We found the soil materials within the walls of the ponds could be assessed and identified in order to optimise the schedule whereby various parts of the walls would be layered back into the pond cavity. By determining a baseline for the natural soil condition of the surrounding landscape using a set of soil pits excavated to approximately three meters, with this depth being deeper than the depth of the pond, a sequence of desirability of soil materials was developed. Analogous horizons, and mixtures of horizons, could then be identified within the pond walls. In order to make comparisons with the baseline soils, these were analysed for electrical conductivity and pH in a 1:5 soil to water extract (EC1:5 and pH1:5), and described for morphological features such as colour, texture and segregations. All the pond sites now have healthy pastures developing that match or improve upon the surrounding landscape.