Objective - to develop new methods and processes for co-production of bioethanol, biogas and fodder based on local feedstock from organic agriculture. We design a farming system with cattle and crop production on 1000 ha of organically managed land including a bioenergy plant.
We evaluate the sustainability of this system in relation to production of fodder and feedstock for bioenergy, its soil fertility and quality as well as its emission of green house gasses; we apply also a farm- and socio-economic perspective. In addition, we design and test the new growing concept, stripe-cropping.
Preliminary results
Bioenergy potential of biomass from stripe-cropping is assessed by means of
i) biogas reactors being optimized for the best combination of manure and energy crops and
ii) different pretreatments of biomass to optimize ethanol production.
Co-production of bio-ethanol and fodder from sprouting wheat grains and whey is tested and shows promising potentials.
A biorefinery for production of biogas, bioethanol and fodder based on biomass from 1000 ha is developed and analysis of energy and material flows as well as socio-economic aspects has been started.
Field trials show that:
1) the stripe-cropping concept with stripes of perennial clover/grass mixtures as well as winter rye/winter vetch mixtures or maize as annual energy crops work well,
2) soil application of biogas residues do not decrease the functional microbial diversity in the short run and the residues are degraded less quickly than the non treated manure and mixture of clover/grass when applied in the same way,
3) soil application of biogas residues reduces the green house gas benefit of growing maize for bioenergy production by up to 70% according to preliminary calculations.
Different models for nutrient, carbon and energy flows are being developed using the experimental data obtained to be able to recommend sustainable ways of using local feedstock for bioenergy production.
