Composting of pig waste and its use as a soil conditioner in horticulture

[Truncated] Piggeries produce a large volume of waste and concerns over the treatment and disposal of this waste have led pig industry organizations, such as the Australian Pig Research and Development Corporation (PRDC) to seek new options which are environmentally compatible. Composting is one option that could help reduce the volume of waste to be disposed of as well as converting the waste into a product that has value as a soil conditioner. A prototype composting system was used as the basis for this project. This system had been set up at a piggery in the south west of Western Australia to test the viability of composting. The project focussed on assessing the value of tests for ensuring the efficiency of composting and to select benchmark tests that could be easily used on other composting systems. It was found that pig waste could be readily composted using an 'in tunnel' composting system. The most predictive tests for monitoring the composting process were the carbon to nitrogen ratio of the compost and temperature and moisture content of the composting waste during and at the end of composting. Overall, the C:N ratio was the most predictive test of the state of decomposition of the compost. Other studies of composting unique waste types, such as slaughter-house waste, have also shown that these three factors are the most predictive of compost decomposition.