Environment, Soil, and Digestate Interaction of Maize Silage and Biogas Production

In this study are presented the possibilities of using maize silage for biogas production. An experiment with maize silage took place over three years (2016–2018) in two localities, Ilandža, Alibunar municipality (L1—Locality 1) and Dolovo (L2—Locality 2), Serbia, and using two variants: a control with no digestate (C) and a variant with digestate, which was organic manure from biogas facilities (AD). In the AD variant, 50 t ha−1 of digestate was introduced into the soil just before sowing the maize. The following traits were examined: plant height (PH), biomass yield (BMY), biogas yield (BGY), and methane yield (MY). The effects of the studied factors (year, fertilization, and locality) on the biogas yield were significant (p < 0.5). The most favorable year for biogas production was 2016 (207.95 m3 ha−1), while the highest values of maize plant height, biomass, and methane yield were recorded in 2018 (2.48 m, 51.15 t ha−1 dry matter, and 258.25 m3 ha−1). The digestate exerted a significant influence (p < 0.5) on the values of all the tested maize parameters in all three experimental years. The biomass yield was positively associated with the plant height, biogas, and methane yield (r = 0.62 *; r = 0.70 *; r = 0.81 **) and positively but nonsignificantly associated with temperature (r = 0.42) and precipitation (r = 0.12). The application of the digestate before sowing improves the anaerobic digestion of maize silage and biogas production.