Row-Intercropping Maize ( Zea mays L.) with Biodiversity-Enhancing Flowering-Partners—Effect on Plant Growth, Silage Yield, and Composition of Harvest Material

Maize cultivation faces some challenges, particularly in terms of low biodiversity in fields. Since maize is a highly efficient and economic crop, it is cultivated on large areas in Germany, with a high share in crop rotation, especially where cattle farming takes place. Such landscapes provide less habitat and food resources for small vertebrates and arthropods. Intercropping maize with flowering partners might have a positive effect on the environment and might promote biodiversity in agricultural ecosystems. Therefore, in two-year field experiments on three sites in south-western Germany, plants were tested for their suitability as intercropping partners in maize crops ( Medicago sativa , Melilotus officinalis , Vicia sativa , Tropaeolum majus , Cucurbita pepo , and Phaseolus vulgaris ). Almost all tested partners produced flowers, except M. officinalis . Intercropping maize with P. vulgaris or T. majus achieved comparable dry matter yields as sole maize, without changes in the biomass quality. For maize-intercropping, site adapted weed control and practicable sowing technique are mandatory, which already exist for P. vulgaris and T. majus . The study shows that intercropping maize with biodiversity-enhancing flowering partners can provide an applicable alternative to sole maize cropping and enhance biodiversity. The large production areas of maize have great potential for ecological improvements in agriculture.