Rooting density of three grass species and eight Lolium perenne cultivars

摘要

Grassland with deeper and denser rooting can take up more nutrients and water, which increases productivity and reduces nutrient losses. The choice of specific grass species and/ or cultivars could be an effective management tool to enhance rooting depth and density. This hypothesis was tested in two field experiments on sandy soil. In experiment I, the root mass, root length and root diameter of Lolium perenne (Lp), Festuca arundinacea (Fa) and Dactylis glomerata (Dg) were compared. In experiment II, the same was measured in eight selected cultivars of Lp, contrasting in terms of ploidy (diploid, tetraploid), production level (high, low) and earliness of production (early, late). In experiment I the results showed that the root biomass in the deeper soil layers (16-24 cm and 24-32 cm) of Fa was significantly higher compared to Lp or Dg. In experiment II, the root length density of the eight cultivars varied between 14.5 to 27.9 cm cm~(-3). Diploid cultivars had a higher root mass, higher root length and lower mean root diameter than tetraploid cultivars. It can be concluded that using Festuca arundinacea and/or diploid Lolium perenne cultivars in grass mixtures can increase rooting depth and density.