Forage type and additive effects on fermentation quality and biorefinery performance of silages

Abstract

The concept of a green biorefinery has recently gained interest and can be defined as a process where green biomass is processed to a variety of products. Most green biorefineries rely on fresh green biomass as the feedstock, but using a stable ensiled biomass could provide benefits. We evaluated the effects of silage additive treatments on silage fermentation quality and performance in a laboratory scale liquid–solid separation to simulate the first step of a green biorefinery. In Experiment 1, red clover and fresh and wilted grass were ensiled without additive or treated with a lactic acid bacteria inoculant or a formic acid based additive. In Experiment 2, grass or red clover were treated with a fibrolytic enzyme, formic acid or a combination of them, and a control without additive was also included. Silage fermentation quality was improved by additive use. Biomass dry matter concentration was negatively related to liquid yield, but effects of additive treatments on the biorefinery performance were minor and inconsistent between different forages. Optimizing agronomic and feedstock conservation management plays an important role for the success and sustainability of the biorefinery process. Good silage management practices with minimal losses during storage should be targeted, but no clear patterns in biorefinery outputs were observed in the current study when different types of additives were used in grass and clover silage production.

Topics from the 2023 EGF Symposium: The future role of ley‐farming in cropping systems, and other recent grassland events

“…The open call last year for papers related to "Green biorefinery" has resulted in several submissions, some of which are published in this issue (Micke et al, 2024;Rinne et al, 2024). As more papers are expected on this topic, the guest editor Prof. Marketta Rinne aims to prepare a future virtual special issue at a later stage.…”