Factors Influencing the Impact of Anaerobic Digestates on Soil Properties

Abstract

Green energy is expected to play an increasingly important role in the energy sector, so the volume of biogas production and the formation of anaerobic digestates is likely to increase in the future. A wide range of biodegradable organic materials are used in anaerobic digesters to produce biogas. This review focuses on the properties of anaerobic digestates and their effects on physical, chemical and biological soil parameters discussing the benefits, limitations and potential risks. Due to the variety of technologies and raw materials used, anaerobic digestates have diverse properties. Therefore, their impact on specific soil parameters, such as bulk density, aggregate stability, pH, electrical conductivity (EC), soil organic matter (SOM) or microbial activity can vary in magnitude and direction. These effects are also influenced by the variety of soils. Although digestates usually have a significant macro- and micronutrient content, their potentially toxic components or high salt content may limit their use. Despite the limitations, the application of anaerobic digestates generally has more advantages than disadvantages. The use of good-quality anaerobic digestates can improve the physical and chemical properties of the soil, increase soil nutrient and SOM content, as well as soil microbial activity.