Sheep are a vital part of agriculture around the world, often grazing in areas unsuitable for other crop systems and are important in regenerative programmes. In addition to providing meat and milk, sheep provide wool, a renewable source of fibre and keratin protein. Wool is sheared from sheep and regrows naturally on a seasonal basis but now faces limited market avenues due to the rise of synthetic alternatives.

Surplus or waste wool can be hydrolysed to produce a liquid formulation rich in peptides and amino acids and applied to crops via existing on farm equipment. Utilising waste wool to extract sources of valuable peptides and amino acids can contribute to the circular economy in agriculture and provide a means of reducing synthetic chemical inputs in crop production.

Our work investigates the use of hydrolysed keratin protein from sheep wool as a biostimulant and the effects it has on yield, crop quality and fruit colouring. Trial data demonstrates that application of hydrolysed sheep wool keratin increases total yield per hectare and enhances colouring in grapes and red pepper. Transcriptomics confirms effects on gene expression and resulting cascades when the formulation is applied as a foliar spray.

As a result, hydrolysed sheep wool is a promising material for integrating into crop production programmes where crop quality and colour is a critical factor.