Maize is wonderful crop to grow for biogas. But imagine an alternative that is cheaper to grow, is a perennial (so doesn’t need drilling each spring) and provides valuable food and habitat for wildlife. It’s these benefits that have attracted a growing number of European farmers to grow silphium, and it’s now appearing in several Lincolnshire fields.Farmer Paul Sheardown has a 165kW anaerobic digestion (AD) plant at Grange Farm near Grantham which needs to be fed 10t of maize silage a day.However, this year, he is supplementing it with silage produced from 30ha of the novel crop Silphium Perfoliatum – or more commonly called the cup plant.
Maize growing
Over the years, Paul has developed a more sustainable approach to growing maize through the use of cover crops and reduced cultivations.After cutting wheat, he strip-tills the ground once he has established a cover crop of black oats and vetch. Then, in the following spring, he direct-drills maize with a precision drill into the cultivated strips.
He opts for early maturing varieties of maize to enable him to harvest earlier, giving more time to drill wheat in the autumn with a Claydon drill.Sometimes Paul has to subsoil wheelings resulting from harvest before drilling the wheat. But by strip-tilling the maize, the ground takes trailers better than if ploughed.
Silphium Perfoliatum is more commonly known as the cup plant. It is a flowering plant in the Asteraceae family, which is native to eastern and central North America.It is an erect herbaceous perennial with triangular-toothed leaves, and daisy-like yellow composite flowers in summer.In Germany, the arable cultivation of the plant is becoming increasingly widespread for biogas production, being a low-input alternative to maize.It also offers benefits to wildlife. The flowers make it an attractive plant for many pollinators, providing pollen and nectar, and the “cups” of water formed up the stems are attractive to insects and birds as a water source.
