Successful maize cropping for forage under rain-fed conditions is predominantly dependant on the meteorological conditions, as well as on the soil type and crop density. The aim of this study was to relate the productive characteristics of forage maize with the quality of the produced silage from crops cultivated on alluvium and hydromorphous black soil, under rain-fed conditions at four plant densities (68–74,000 plants ha –1). The highest biomass yields were obtained at higher densities, mainly on hydromorphous black soil. The dry matter yield and cellulose content were strongly influenced by the D coefficient (coefficient of fractal dimension). Owing to the meteorological conditions, maize forage cropping on alluvium could be associated with a lower crop density with earlier harvesting, while the management recommendation for hydromorphous black soil could include a high plant density with a longer vegetation period.