Researchers at TEAGASC are examining residues from dairy processing for use as organic fertiliser.
Wastewater created during the production of butter, cheese, milk powders, cream, and whey powders at milk processing facilities must be treated. This results in the generation of dairy processing organic residues (DPOR), which must be managed; approximately 128,636 tonnes were generated in Ireland in 2015. Due to the abolition of European milk quotas in 2015, milk production in the Irish dairy sector is expected to increase by 50% by 2020. This will create an added challenge of tackling more DPOR generation. Recycling of DPOR to land provides for a circular economy and should also provide farmers with an organic fertiliser. However, there is as yet no systematic study of the recycling of DPOR from an Irish perspective in terms of nutrient recovery, agronomic benefit, and associated environmental impacts.
Current research in this area within the Teagasc Environment Research Centre is focusing on the recovery and recycling of agri-nutrients (nitrogen (N), phosphorus (P), and potassium (K)) from DPOR. In particular, this project aims to investigate and develop the comprehensive physicochemical characteristics of DPOR from the Irish dairy processing industry and, subsequently, to identify fertiliser (N/P/K) replacement value and associated agri-environmental impacts from recycling of DPOR through controlled laboratory, micro-plot rainfall simulation and field-scale agronomic trials.