Arable cropping uses considerable amounts of mineral fertiliser, much of which is derived from non-renewable sources. At the same time, a considerable amount of nutrients are potentially available to the arable sector through recycling from other agricultural sectors and from other sectors.

While many growers will be familiar with the use of products such as animal slurries and manures the use of more novel products from various industrial streams will be less familiar to most growers. Work on integrating these products into fertiliser programmes has been ongoing in Teagasc for a number of years as part of a number of European funded projects.

These products have the potential to reduce fertiliser costs for the grower as well as reducing the carbon footprint of the growers produce (recycled nutrient sources will generally have a lower embedded carbon footprint in them on arrival on farm compared to mineral fertilisers).

However, there are challenges which need to be addressed for their usage. Firstly, there is a wide diversity of products available, both liquid, semi solid and solid each with their own handling and spreading characteristics.

Products available include liquid digestate coming from anaerobic digestion plants, a wide range of dairy processing sludge coming from dairy processing plants, processed poultry manure, separated manure solids, spent composts, municipal sludges and struvite coming from waste water P recovery processes.

Secondly the total amount of nutrient in these products and the percentage of that nutrient that will be available to a crop can vary considerably between these products and even between different batches of the same product. Work within Teagasc has focused on providing information on these issues and demonstrating their use in practice to provide the necessary information to allow these products to be used with confidence when devising fertiliser programs for their crops.

What will you see at the open day?

  • A range of recycled bio-based fertilisers.
  • Results from a long-term, now seven-year study, where bio-based recycled nutrients were used to provide a portion of the crop nutrient requirement.
  • A spring barley crop grown using some of these products as part of a balanced fertiliser programme side-by-side with a crop grown exclusively with mineral fertilisers as part of the Renu2cycle project.
  • You can meet experts to discuss the pros and cons of these fertilisers and you can get advice on how such recycled fertilisers could be incorporated into fertiliser programmes.