The utilization of plants’ biomass as a renewable energy source is an increasingly common tool to mitigate climate change and decrease the reliance on fossil fuels. However, an essential amount of ash is generated as a result of the biomass processing and is frequently discarded to landfills. This waste poses economic and environmental challenges in promoting alternative energy production and highlights the urgent need to establish an effective waste management strategy. Ash recirculation in soil is among the sustainable and eco-friendly approaches, which prevents the loss of valuable minerals and simultaneously restores substantial levels of soil micro- and macronutrients taken up by plants during vegetation. The application of ash to soil decreases the demand for landfilling and concurrently enables the return of essential nutrients into ecosystems. Biomass-derived ash significantly enhances soil health, mitigates soil acidification, stimulates plant growth, and boosts crop yields. A critical aspect of sustainable ash valorization is evaluating its risks and possible negative impact on the environment. This chapter overviews the implementation of the appropriate management approaches toward ash valorization to ensure its safe and beneficial utilization.