Evaluation of the Use of Biogas Plant Digestate as a Fertilizer in Field Cultivation Plant

Abstract

Biogas production in an agricultural biogas plant is connected with generation of large amounts of post-digestion liquid as a result of anaerobic decomposition of plant debris. Due to its physicochemical properties, post-digestion liquid can be used as a fertilizer. A possibility of agricultural utilization of digestate as a fertilizer was investigated. Digestate obtained from an agricultural biogas plant was tested for the content of macroelements and heavy metals. The content of macroelements was also examined in the soil before and after digestate application. Digestate was used for in the cultivation of fodder winter rape and winter wheat. The content of macroelements as well as the content of protein in the grains of winter wheat fertilized with digestate were on the same levels as in the grains of wheat fertilized with mineral fertilizers. Similar tendency was also observed in winter rape grains. Digestate utilization as a fertilizer brings tangible benefits in agricultural production and can reduce the negative effects of mineral fertilization and contribute to development the sustainable agriculture. The study has shown that digestate can be used as a fertilizer.