Soil Stabilisation – Why It Is Important
Definition: Soil stabilisation involves the use of stabilising agents (binder materials) in weak soils to improve its geotechnical properties such as compressibility, strength, permeability, and durability.
Soil is the foundation and essential natural resource for all life to survive. Therefore it is vital to monitor and take into consideration actions that may impinge on the soil structure. One of the largest global disruptions of the earth’s substrate crust is the mining of natural resources, often followed by large civil and infrastructure projects. The consequences of disturbing topsoil during stripping, stockpiling, and reinstatement is the flow-on effect of these activities, which can cause environmental issues such as a poor – unlikely seed germination, erosion and dust concerns.
Fortunately, the Australian mining industry is properly aligned with the global pursuit of sustainable practices and therefore must maintain the government legislation which stipulates that ‘the ecosystem including the soil and vegetation are to be returned to their natural form upon closure of the specific site location.’ Rehabilitation in conjunction with revegetation should be a part of an integrated management program throughout all phases of resource development, from exploration through to construction and closure.
Despite many companies following the correct procedures in preserving the original topsoil, the soil profile may be affected when the land surface under scrutiny is subject to different environmental factors that may alter the soil; density, nutrient levels and capacity to hold water. When these variables are changed, the structure of the soil becomes unbalanced, making it extremely hard to produce vegetation and may cause environmental issues as a result.
Based on extensive experience in solving some of the harshest environmental issues across the nation, Spray Grass Australia understands firsthand the complexity of soil stabilisation for rehabilitation purposes. The team recommends that your site area should be analysed as soon as possible – based on the ideology that “prevention is better than the cure”.
Every project site is unique; therefore, in establishing an effective soil stabilisation strategy, it is crucial to understand and extract as much data as possible from the location. This process revolves heavily around soil testing, analysis, 3D multi-spectral and thermal drone mapping.
Soil testing is an essential part of the assessment process, which looks closely at the physical, chemical and biological disturbances of the soil such as pH, fertility, microbial community and various soil nutrients. Once an educated understanding is made, the productivity of the soil can be restored by creating a tailored amendment solution that will recover its ecological integrity by counterbalancing any significant changes that may affect the soil’s ability to facilitate growth.
There are three essential nutrients that plants require from soils, without any which one they could not survive, these are referred to as the primary macronutrient: nitrogen (N), phosphorus (P) and potassium (K).
Nitrogen (N) – Nitrogen is largely responsible for the growth of leaves on plants and provides the chlorophyll for photosynthesis.
Phosphorus (P) – Phosphorus is responsible for root growth and flower development and aids in the structural strength and quality of crop and seed production.
Potassium (K) – Potassium is the nutrient that helps the overall functions of the vegetation perform correctly and contributes to the overall growth and development.
Often, soils lack these nutrients, either naturally or as a result of engineered or environmental factors. Soil lacking in these and other nutrients such as iron, zinc, calcium, manganese, copper may require to be supplemented to create the ideal environment and encourage growth. This is most often completed in the form of NPK fertiliser, which is commonly added to hydroseeding and hydromulching solutions. These methods utilise mine specific HydroTrucks, which agitate the mixture to ensure an even and consistent mix of ingredients which maximises erosion protection and soil stabilisation. Depending on how depleted and lifeless the soil is, a topsoil enhancement such as EnviroSoil, may be required before the application of fertiliser and seed.
Soil stabilisation must go beyond establishing a solid substrate foundation by considering the potential integrated functions for a long-term ecosystem. The stabilisation efforts should establish the building blocks for a self-sustaining system that supports healthy vegetation development. Whether you are in the planning, implementation or completion phase of your project, it’s never too soon to get in touch with the team at Spray Grass Australia to discuss your rehabilitation and soil stabilisation works.