Can we develop novel algae fertilisers from whisky co-products to produce barley sustainably?

Inorganic fertilisers are essential for global food production, but their use is unsustainable due to depleting mineral reserves, harmful surface mining, and energy intensive processing. To maintain crop yield and quality while decreasing our impact on the environment, alternative, sustainable fertilisers are required. Fertilisers based on microalgae (single-celled, photosynthetic eukaryotes) are being considered as microalgae have a fast generation time, sequester atmospheric carbon when growing, and have the potential to clean up nutrient rich wastewaters when using them as a medium for growth, allowing for nutrient recycling within supply chains. Nutrient recycling is of particular interest to the Scottish Whisky industry, who see the potential sustainability benefits of growing algae on their co-products of pot ale and spent lees, then using this as fertiliser for barley. This project investigates the use of microalgal fertilisers as a nutrient source for barley at a range of scales, from the genes which help plants take up and utilise different types of fertilisers, to field trials to understand the impact on yield. The effect of algal fertiliser on the growth and development of plants will be quantified in glasshouse and field trials, by comparing yield components between plants grown with algae and standard mineral fertiliser. Grain from these field trails will be malted and analysed for spirit yield predictors. To identify genes that play key roles in the use of algae as a fertiliser, which could be used as breeding targets, the changes in gene expression in plants grown with algae or mineral fertiliser will be compared. This project will also optimise a growth medium of pot ale and spent lees to maximise growth of algae for use in glasshouse trials. Overall, this project will provide a proof of concept for use of microalgal fertiliser on barley, improving the sustainability of barley growing, distillery co-product treatment and nutrient recycling.