The ReNu2Farm project aims at increasing recycling rates of the plant nutrients Nitrogen (N), Phosphorus (P) and Potassium (K). P and K are limited and finite resources, and production of N fertilizers is energy-intensive. Despite recovery technologies having been developed, the use of recycling-derived fertiliser products by farmers is limited until now. The ReNu2Farm paper presented at CERI2020 focused on the farmers’ attitudes to RDF (recycling derived fertilisers) sources. As CERI2020 is a national conference, it was interesting to determine the Irish survey participants’ opinion on different sources of RDFs compared to those from the other NW Europe countries. Therefore, the survey results from Ireland were directly compared to the combined results collected from participants in NW Europe. From the analysis of the farmers’ survey participants in Ireland are more willing to accept RDFs from household food waste and sewage sludge compared to those in NW Europe. While their willingness to utilise RDFs from animal waste, food industry waste and urban green waste sources is on par with the other NW Europe countries. In addition, although participants in Ireland have heard of RDF products, such as compost and sewage sludge, it is also evident that some of those in Ireland have not heard of other RDF products as much as their NW Europe counterparts. As part of the questions and answers session after the presentation, why there is such a low uptake of these products from recycled sources in Ireland and the willingness of those in Ireland to use RDFs was further discussed.
The Phos4You project addresses the phosphorus (P) challenge. P is an essential nutrient and although it is a finite resource on earth, P is largely wasted today. The EU acknowledged this by adding phosphate rock to its list of critical raw materials in 2014. There is a need to boost the use of secondary raw P. The Phos4You paper presented at CERI2020 highlighted the development of a mineral-based phosphorous deficient artificial growing medium, to test the performance of recovered phosphorus fertiliser. Pot trials were run on different growing media types to evaluate Struvite recovered from municipal wastewater and compare it to commercial fertiliser triple superphosphate. It is highlighted that recovered Struvite has significant potential to be used as commercial fertiliser. CIT has created and developed a growing medium to establish a uniform platform to test the P availability of a variety of recovered phosphorus fertilisers, by reviewing their effects on potted grass dry matter production. The suitable growing medium has insignificant levels of available phosphorus to prove that the absorbed P through the roots originated from the applied fertiliser and not from the residual P present in the growing medium. Three variations or generations of mineral mixtures were tested to form a suitable growing medium with insignificant levels of available phosphorus and suitable chemical/ physical properties to supply plant roots with the required air, water and nutrients. The growing medium blend included kaolinite clay, bentonite clay, granite/marble dust, natural silt, granite sand and horticultural sand. Further development of the growing medium is still in progress to achieve the desired characteristics of low P content, optimum pH, good aeration and drainage and uniform consistency of blend.
CERI2020 was a remarkable success and the incredible work by researchers in CIT and their Interreg partners was immediately evident. The high-quality research work on all three projects is well worth checking out and the peer-reviewed conference papers are available through the link below.
Conference proceeding link https://www.dropbox.com/s/wtlfyn8q28hz0f4/CERI%202020%20Proceedings%20%28Print%20Ready%29.pdf?dl=0