Intensive Lightweight Topsoil

A yellow, dry, non-plastic, and non-calcareous sand with a single grain structure, free of stones, unusual odours, and visible contamination. Laboratory tests revealed the sand was slightly alkaline, non-saline, and contained a low level of organic matter. The soil demonstrated high permeability and sufficient porosity.

The sand sample exhibited a narrow particle size distribution, predominated by medium sand, deemed acceptable for maintaining porosity and minimising particle interpacking. The sample was stone-free. The sand's permeability was high, indicating good drainage performance, though potentially requiring irrigation to compensate. The sample displayed reasonable total porosity, with a good water-holding capacity. A re-compacted California Bearing Ratio (CBR) test indicated the sample could achieve a minimum CBR of 51%. The sample was slightly alkaline with low salinity and low organic matter content.

Based on the findings, the horticultural and geotechnical properties of the sand were considered suitable for use as a structural subsoil for tree planting in hard landscape situations.