A comparison of surface applied granulated biosolids and poultry litter in terms of risk of runoff water quality on turf farms in Western Sydney, Australia.
Eldridge SM, Chan KY, Barchia I, Pingelly PK, Katupitiya S and Davis JM (2009) A comparison of surface applied granulated biosolids and poultry litter in terms of risk of runoff water quality on turf farms in Western Sydney, Australia. Agriculture, Ecosystems & Environment, 134: 243-250.
Available online: http://dx.doi.org/10.1016/j.agee.2009.07.007
Granulated biosolids are pathogen-free product of sewage sludge treatments in the form of granules and used as a fertiliser. This product and poultry litter (the current turf farm practice) were applied on couch turf to study the runoff water quality. A week after the application a simulated rainfall was applied and all runoff water was collected and analysed for a range of important water quality parameters. The most significant result from this study was the finding that runoff water samples from the poultry litter treatment plots were found to contain 10 times more total phosphorus and dissolved phosphorus than that found in the runoff water samples from the biosolid treatment. The relationship between application of total phosphorus loading and runoff water total phosphorus concentration was significantly different between the biosolids and poultry litter products, reflecting the importance of the chemical nature of the applied phosphorus in addition to the total loading. The phosphorus in the poultry litter was much more easily mobilised and transported in runoff than the biosolids phosphorus. For surface applications of these organic wastes, bicarbonate extractable phosphorus loading provided a better indication of runoff phosphorus contamination risk in the first flush of runoff, than total phosphorus loading. The runoff from the biosolid treatment plots also had lower levels of ammonia and salinity than the poultry litter plots, although both treatments had moderate levels of dissolved organic carbon in their runoff. Heavy metal levels in the runoff were below guideline limits for both organic amendments, while runoff pathogen levels were highly variable. The findings highlight the potential benefits of using granulated biosolids as an alternative surface applied organic nitrogen fertiliser on turf farms for its lower risk to surface water quality as compared to poultry litter, the current practice.