Research project NiCo

Trace elements by energy crops – mass flux and recommendations for an optimized process biology in biogas plants

Due to the low trace element concentration (especially cobalt and nickel) in maize, sole maize silage input in biogas plants is insufficient to achieve an optimum of methanogenesis. In order to prevent a reduced biogas production, more than 3.000 biogas plants in Germany currently use industrial additives. This method causes an increase of expenses and puts operators as well as the environment at risk. Compared to maize, alternative energy crops accumulate considerably more essential trace elements. The hypothesis is that the admixture of alternative energy crops ensures a sufficient trace element supply for the fermentation process in biogas plants. The agronomic value of the alternative energy crops is represented by the index IrA. IrA consists of a multitude of ecological, economical und social aspects. The underlying hypothesis will be verified by the use of laboratory digesters. Correlations between element concentration, process data and microbial activity will reveal basic phenomena.

Subproject 2: Index of relative agronomical suitability of energy crops (IrA)
In 2-year field experiments (2014/15 and 2015/16) in Göttingen (Loess) and Schoningen (sandy silt), classical and alternative energy crops are tested and numerous parameters are collected. Representatives of crops high in trace elements e.g. perennial flowers, a rye-vetch mixture and winter faba bean as winter crops and summer faba bean and amaranth as summer crops are tested. These energy crops will be evaluated using the index of relative agronomical suitability (IrA). IrA considers e.g. dry matter and methane yield, trace element concentration, root mass, mineral nitrogen in the soil during winter und water content in the soil after harvest. Cultivation costs and public acceptance of energy crops in population are also included. After the winter crops maize is grown in a double-cropping system to evaluate the effects of the preceding winter crops. The index IrA provides a decision-making support for the selection of alternative energy crops. The numerous parameters taken into account by IrA enable farmers to find the optimum cultivation variant for their location.

Person in charge
M.Sc. Katharina Hey

Project duration
1st of December 2014 to 30th of June 2018

Federal Ministry of Food and Agriculture via Agency for Renewable Resources (FNR)
Funding code 22019014

Interdisziplinäres Zentrum für Nachhaltige Entwicklung (IZNE)

Department of Sedimentology & Environmental Geology at the Geoscience Centre, Georg-August-University Göttingen

Deutsches Biomasseforschungszentrum (DBFZ)

Helmholtz Centre for Environmental Research (UFZ)

Website AG Bioenergie und Umwelt