Growing rapeseed in mixed cropping with cereals

Summary

Yields of mixed cropping systems of winter rapeseed (Brassica napus) with winter rye, winter wheat and winter barley in organic farming are reported by the example of a one year field trial in Trenthorst, North Germany. The trial was established as per¬petuation of trials in the years before with different seed densities and row distances due to very low yields of both components to increase the overall yield of the mixtures. Winter rapeseed was heavily suppressed by the cereals when grown in mixture with rye. The winter rapeseed yields were more adequate in relation to the chosen seed reduction in combination with wheat. In systems with delayed drilling of the cereals between rows of rapeseed, wheat and barley had problems in field establishment and rapeseed yields were over-proportional in relation to the chosen seed reduction. Land equivalent ratios (LER) were around 1 in all systems. The use of those mixtures as practicable yield buffer in organic farms needs further evaluation.