Without detailed knowledge of site properties, there is the risk, that measures for establishing vegetation and slope reinforcement remain without success, and thus, do not fulfil their functions. Unfortunately, it can be observed, that seed comparatively often does not come up, or if it comes up, does not grow properly. Then, there are slope areas, which - in spite of applied soil bioengineering techniques of slope reinforcement - have slipped off or show erosion grooves.
Frequently, insufficient knowledge of the site properties is the reason. This leads to the application of unsuitable or wrongly dosed components like seed, fertilizers and soil conditioners or inadequate reinforcement constructions not suited for the respective site.
A detailed knowledge of the site properties of the area to be reclaimed, revegetated or reinforced, decisively contributes to avoid imperfectly sowed vegetation and slope reinforcements.
A survey of the most important site properties:
- Inclination and exposition
- Slope length
- Rock or sediment type
- Soil type and grain size distribution
- Soil layers and soil structure
- Soil pH
- Soil nutrient content
- Salt content, ion activity
Most soils and substrates usually require no detailed analyses in the laboratory, as the relevant parameters generally can be sufficiently determined or approximately evaluated by an inspection, a sample of the soil and a glance at the geological map.
Due to our decades-long activities and comprehensive project experience we are perfectly acquainted with sites in all natural and cultural areas from the coast to the Alps, from the Rhine to the Oder and far beyond those, even with sites in other climates.
Merely extreme sites especially hostile to plants, like e.g. tertiary sands of lignite opencast mining, hard coal mining waste, technogenic soils, polluted areas and often road sides (salt), frequently deserve a close soil-chemical analysis.
Particular important is a professional on-site soil preparation, e. g. according to the German DIN 18915. Soil compaction and planished slopes should be avoided as this would result in germination and growth depressions!
Contact us, we look forward to advising you!
Click images to enlarge
In case of difficult sites - the graphs in our example show the nutrient contents of coal mining waste low in nutrients and containing pyrite - the concept for establishing vegetation extraordinarily benefits from soil analyses. While the supply with potassium consistently is good, the undersupply with phosphate is abundantly clear in soil layers from 20 cm downwards. Such findings are decisive for the estimation of root growth and vegetation development, and thus, for the selection of the adequate procedure for reclamation of the respective site.
Professional advice regarding the on-site soil preparation is important for the revegetation success. The picture shows a very plane prepared clayey slope surface which should be avoided unconditionally. The strong surface leveling causes clogging of pore space and reduces water infiltration, which interfere plant growth. At dry weather conditions, a hard crust-like soil surface develops. Rooting is constricted.
Characteristic pH graph for artificial pyrite-containing soils in mining areas. Within only a few years soil pH drastically decreases in the upper soil layers caused by the oxidation of iron disulfides (pyrite, marcasite). The acidity can obtain phytotoxic values up to pH 2-3. Soils like this can be reclaimed successfully by applying suitable amelioration measures and site adapted seed blends.