Abstract

Sheep wool unsuitable for textile use is classified as special waste. However, it has the potential to be used as a sustainable and inexpensive input in agricultural production. This review comprehensively evaluates the yield, product quality, and bioactive content of raw wool, pellets, hydrolysates, and carbonized derivatives after their use as organic fertilizers, soil conditioners, and mulches. Studies have shown that sheep wool-based materials function as slow-release organic nitrogen sources and increase the soil's water-holding capacity. This feature has resulted in yield performance comparable to commercial organic fertilizers. Some studies have reported maintaining product quality, while others have reported improving it. When applied as mulch, sheep wool improved the sugar-acid balance in fruits and increased phenolic and flavonoid content. Sheep wool-based soil conditioner application supported yield and quality. Variations in yield and quality were observed depending on the product and application. Overall, it was concluded that the use of sheep wool as an agricultural input does not lead to yield or quality loss and can be used as an inexpensive agricultural input.

Keywords

organic fertilizer, crop yield, product quality, bioactive compounds, sustainable agriculture, circular economy