Reducing Mineral Fertilizer Usage: Utilizing Sheep Wool and Alkaline Hydrolysate for Enhanced Sugar Beet Cultivation

Abstract

The effects of sheep wool (SW) and its hydrolysate (H) on the vegetative growth, root development, nutrient concentrations and sugar quality parameters of sugar beet grown under full (FF) and reduced fertilizer (RF) conditions were investigated. The treatments were as follows: FF, FF + SW (4 g kg⁻¹) and FF + SW + H (4 g kg⁻¹ + 4 ml kg⁻¹), RF, RF + SW (4 g kg⁻¹) and RF + SW + H (4 g kg⁻¹ + 4 ml kg⁻¹). The shoot and root samples were collected at two-week intervals from the beginning of root development to harvest. In these samples, temporal change of leaf mineral element concentrations and sugar quality parameters of the sugar beet roots were determined. Reduced fertilizer application did not have a negative effect on shoot and root growth. SW and SW + H treatments significantly increased total shoot (40.2 and 52.1%) and root yield (4.59 and 7.61%) of sugar beet in reduced fertilizer conditions. Nitrogen (N), calcium (Ca) and magnesium (Mg) concentrations of shoots increased significantly with SW and SW + H applications. Similar increases were also observed for phosphorus (P) in the 3rd sampling period. The treatments did not have an effect on potassium (K) concentrations of shoots but some increases observed in Na and α-amino N concentrations depending on SW and SW + H treatments. The SW and SW + H treatments significantly reduced sugar existence and refined sugar existence. On the other hand, the treatments had no significant effect on the refined sugar at harvest periods. Sheep wool and H can be incorporated into organomineral fertilizers, potentially reducing excessive fertilizer use and improving fertilizer efficiency.