Effects of digestate on biomass of a selected energy crop and soil properties.

ABSTRACT

BACKGROUND: A large number of digestates have not been fully utilized due to a lack of scientific, reasonable guidance, as well as imperfect technology. Hybrid giant Napier has great potential for use as a type of energy plant. As such, this study investigated the effects of digestate on the growth of a candidate energy crop and examined whether digestate was an ecologically viable means for soil restoration. RESULTS: The results showed that the total yields of all treatment groups receiving irrigation of digestate were higher (5.19-26.00%) than those of the control. The total phosphorus, total potassium, available nitrogen, available phosphorus, and available potassium content of the soil had also increased after digestate application, compared with the control. Urease activities for all treatments increased 15.28 to 69.44% more than that of the corresponding control. Soil dissolved organic matter (DOM) mainly contained humic-like and fulvic-like components through the application of digestate. More fluorescent components were also identified by two-dimensional correlation spectroscopy (2D-COS). These fluorescent components can improve the aromaticity and molecular weight of soil DOM so as to improve soil quality. CONCLUSIONS: Digestate improved not only the aboveground biomass accumulation, but also the chemical properties of the soil, which was an appropriate strategy for restoring soil quality and contributing to the sustainable development of marginal. The long-term impact of digestate application on soil quality will require additional long-term experiments. © 2020 Society of Chemical Industry.