3.3 Example Grove Seedings
Regarding a quick reinforcement with methods of bioengineering, seedings with grass and herb blends are superior to those ones with seeds of trees and bushes. In the long run, however, groves with their obviously deeper reaching root system and their protecting foliage provide particularly effective slope reinforcements. To achieve a short-term erosion control and a quick vegetation cover, low portions of nurse grasses, herbage and leguminoses, which are no threat to the grove seedlings, are added; the intermixture of grass species or grassland species is not suited, as this meant an enormous competitive pressure for germinating and young groves, which would be suppressed almost completely. Topsoil and soils composed of fine grains (silt, loam) generally offer quite good growing conditions to grass and herb species; thus, groves will only have a very small chance to develop under such a strong competition. Grove seedings on topsoil, silty and loamy soils are not to be recommended.
A sufficiently thick mulch layer is of great importance to achieve adequate germination results. In the technical literature, coats of straw mulch with up to 600 g/m² are recommended; according to experience, this amount is optimal for grove seedings, the minimum amount ought not to be less than 400 g/m².