THE POTENTIAL FOR BIOSOLIDS AS SOIL CONDITIONERS AND FERTILISERS IN ARBORICULTURE

Summary Biosolids are used extensively as effective soil conditioners and organic fertilisers in both farming and reclamation of ex-industrial and brownfield sites. However, there has been little attempt to introduce biosolids into amenity horticultural practices. A field trial with Betula pendula Roth. (Silver Birch) carried out at the Imperial College London Field Centre, Silwood Park, Ascot has demonstrated the nutrient value and soil conditioning properties of biosolids to trees. In addition to organic matter, they also provide substantial amounts of plant available nitrogen (N), phosphate (P), sulphur (S) and micronutrients. Composted biosolids also contain significant amounts of potassium (K). Enhanced treated biosolids have potential for application to areas where there is significant public activity, as these biosolids are treated to destroy microbial pathogens. Conventionally treated materials may be used with land application and restrictions exist for this type of sludge product to control path...