Effects of digestate from anaerobic digestion on Sorghum bicolor L. production and circular economy

The aim of the research was determination the efficiency of application 50 t ha-1 digestate from the process of anaerobic digestion on the productivity of sorghum (Sorghum bicolor L.) on moderately degraded (calcic gleysol) and fertile (chernozem) agricultural land, in southern Banat, Republic of Serbia. In the field experiment during three years digestate amendment led to an increase in the number of leaves by 28.56% and plant height by 5.34%, which led to an increase in yield by 3.40%. The maximum yield was 2018 (41.74 DM t ha-1) on chernozem. The yield of sorghum was lower on calcic gleysol compared to chernozem by 5.43% and was in positive, medium and very significant dependence on precipitation (0.61) and in positive significant correlation with digestate (0.53) and plant height (0.59). Biogas yield reach 157.05 Nm3 t-1 (9582 Nm3 ha-1) on chernozem with digestate. Digestate had a statistically significant positive effect on all tested characteristics of sorghum as well as biogas yield during all three experimental years. The use of digestate as a by-product in the process of producing biogas based on silage of sorghum, allows the substitution of mineral fertilizers and remediation of damaged soil, which contributes to sustainability from the bio-economic and environmental aspects.