Problem-solving the natural way
Erosion of the landscape can be a serious problem whether it is caused by wind, water (nature) or human activity. For many years the solution has been to pile quantities of stone, concrete or plastic membranes, nets or mats into the ground to try and control the degradation of soil……but there is a better way one that has seen a huge increase in uptake over the past 10 years or so.
The use of natural materials to bridge the gap between bare or unstable ground and the natural stabilising effect of established vegetation has been fully recognised as an environmentally sound, effective and aesthetic way to solve potential erosion problems.
We have all seen the results of large scale erosion cause by de-forestation and the same principle applies here if there is no vegetation then the exposed ground is much more susceptible to degradation. The use of natural materials designed to allow the establishment of vegetation as a stabiliser is an extremely effective low-cost way to prevent erosion plus it brings added benefits in terms of habitat creation and biodiversity, aesthetics (the materials look ok left uncovered) and reduced potential for pollution. Plants quickly provide sustainable long term erosion protection – stems and leaves absorb rain energy (reducing erosion from raindrop impact), slow down water runoff and trap sediment, and cushion the impact of foot or vehicular traffic. In most circumstances, biodegradable erosion control is preferable to any permanent material such as plastic. Natural materials provide a much lower rate of soil loss boosting water retention which promotes vegetation growth. Permanent plastic membranes have a smooth slippery surface and no capacity to absorb and retain water, plus they look unattractive and do not degrade.
How to stabilise surfaces prone to degradation?
Concrete, stone, steel mesh and mechanically fixed solutions to erosion are often seen on large civil engineering projects such as road construction but for house builders, developers and landscapers at a smaller scale these are not viable options. For these users, the most commonly available (and used) geotechnical solutions are synthetic woven or non-woven materials made from polypropylene. These products are ubiquitous from small handy packs in garden centres to larger rolls from builder’s merchants and are used to solve any number of problems from weed suppression to soil strengthening, ground stabilisation and erosion control. It’s worth a little diversion to look at their manufacture and use as it highlights why the shift to natural products has been so popular over recent years
Natural vs synthetic: the problem with polypropylene
Polypropylene can be used as either as a woven textile or non-woven spun fabric. Polypropylene is strong and very durable. It is highly resistant to photodegradation and will not decay for millennia and so appears ideal for use in the ground as a barrier, but apart from its unsightly nature the very fact it has such a long life is an issue, and it all starts with the material itself, polypropylene.
Most plastic is manufactured from petroleum the end product of a few million years of natural decay of once-living organisms. Petroleum's main components come from lipids that were first assembled long ago in those organisms' cells. So you could ask the question is, “if petroleum-derived plastic comes from biomaterial, why doesn't it biodegrade?”
The answer lies with the manufacturing process where a crucial manufacturing step turns petroleum into a material unrecognized by the organisms that normally break organic matter down.
When heated up in the presence of a catalyst, individual chemical units (monomers of propylene) link together by forming extremely strong carbon-carbon bonds with each other which results in polymers (which are long chains of monomers) bonded together to form polypropylene.
The problem here is that nature works by building things up and breaking them down and nature doesn't make things like polypropylene; it is unrecognisable to pretty much every living organism as food there simply aren't the metabolic pathways to degrade it and so it has a high level of persistence.
But we use them because they are relatively cheap (unless you buy handy packs from garden centres) and alternatives are not mainstream products.
“The village car park had a membrane put in round the trees when the resurfacing was done, it all looked great for a while but now it looks shabby and unkempt with black membrane sticking out, we have tried to remove it but it’s impossible so we're stuck with it”
When given the choice it’s hard to find any situation where natural materials don’t offer significant benefits over synthetic alternatives, hence their increasing popularity.
Natural ground engineering materials are mainly made from three plants, coir (coconut fibre), jute (which comes from the white Jute plant, Corchorus capsularis, also used to make hessian and burlap) and straw (from a range of cultivated cereals and grasses) the materials are either supplied pure or as a blend.
Additions to the natural fibres may be starch-based backing membrane used to stop light penetration or re-cycled plastic threads as a binder. All the materials used in a natural solution will biodegrade over a period of time, this can be short, 12 to 18 months for lighter jute fibres and up to 36 months for heavier coir materials. The degradation time is a key to ensuring the effective transition between installation and the establishment of vegetation at which point the matt, net or blanket will have done its job.
“By using natural materials to stabilise our drainage channels we ended up with a secure protected a long lasting solution that looks completely in harmony”
One of the principal advantages of natural materials is their resistance to soil loss under rainfall. A natural product’s ability to retain water, promote vegetation growth and stabilise soil, is what makes them the best option to rapidly establish a root ball of vegetation.
Permanent plastic meshes do not control soil movement as well as biodegradable fibres with a greater surface area, and rougher texture. Even in the main areas where a permanent mat was previously the preferred option, higher water velocities, steeper slope angles and greater tensile strength all have biodegradable options available.
A better solution for weed suppression, moisture control, soil stabilisation, erosion control, and general landscaping, to ensure that nature is given the best opportunity to re-establish is our complete range of natural fibre products.
For most applications re-establishing natural vegetation is the ultimate design aim when landscaping a project especially if this includes problems of erosion control or soil stabilisation re-establishing
All grasses will develop a root matrix which helps reinforce the topsoil binding it to the subsoil below; this means the root system improves drainage and soil aeration so reducing the movement of soil particles and consequent erosion or degradation.
When planting with trees or shrubs they also provide similar protection but with the added benefit of giving deeper subsoil reinforcement.
Ecomerchant have developed a range of natural materials for use on the small commercial to domestic scale which offers short, medium and long term support to assist natural development of plants and grasses which will provide the ultimate long-term and sustainable outcome.
Unlike synthetic materials which do not degrade and remain unattractive all Ecomerchant’s natural materials degrade in harmony with the development of the vegetation. The conditions that accelerate decomposition of the blankets, nets and nets i.e. warmth and moisture, are also the conditions in which grasses and plants increase growth.
Other adaptations are pre-seeded matting, an economic and simple way of rapidly achieving an attractive grassed surface especially for watercourse banks and exposed steeper slopes, and mulch mats to suppress weed growth.
Pre-seeded mats are available in a variety of straw and coir fibre combinations, which contain seed, fertiliser, dry micro-organisms and in some cases a layer of topsoil enabling germination and vegetation establishment to take place in the minimum possible time. The matting provides protection from inclement weather and other forces that would compromise unprotected planting.
“Jute netting was the perfect solution for an exposed bank left after we put in a new access road, in just one year the transformation was astonishing, so much better than any of the other options we looked at”
Mulch mats enhance growth without the need for further mulching, chemicals or long term maintenance. The Coir upper layer blends with landscaping protects the UV degradable bottom membrane from ultra-violet light, controls water run-off from gradients and regulates soil temperature.
All natural geotextiles can be fixed using biodegradable fixings, there is a choice between Eco Pegs made from a vegetable starch based plastic for most standard applications or wooden stakes for steeper and softer ground conditions. These are the last link in the biodegradable chain removing the need for large numbers of metal pins that remain in the ground after the material they secured has returned to nature.
Where a natural solution is required or the ugliness of synthetic products is a factor Ecomerchant easy to use 100% natural range of mats, nets and blankets will always provide the best option for those who value a truly natural and effective outcome, by using biodegradable erosion control materials we are enhancing rather than compromising the environment we work in.
- Low-cost option
- Easy to use
- Look good in use unlike plastic or synthetic barriers
- Reduces plant stress ensuring very low plant losses
- Non-chemical weed control for many seasons
- Allows solar radiation to raise and maintain the soil temperature for fast growth
- Avoids nitrogen sink effect experienced with bark mulches
- Eliminates the need for surface coverings such as bark or gravel
- Smaller sizes ensure economical use
- Low maintenance costs
100% natural fibre netting for short term vegetation establishment on banks and slopes up to 30 degrees. Typically lasts for up to 2 years site and weather dependent.
100% natural fibre netting to ensure long term surface stability on steep problem areas, exposed sites and watercourses. Typically lasts for up to 3 years site and weather dependent.
For slope and embankment stabilisation, especially around watercourses, streams and ponds, 100% natural fibre, promotes rapid vegetation establishment. Pre-seeded options available. Typically lasts for up to 2-3 years site and weather dependent.
100% natural, plastic and chemical FREE mulch mat with a light barrier. Moisture control, weed control, soil erosion protection. Typically lasts for up to 3 years site and weather dependent.
100% recycled material and recyclable. The multipurpose peg for garden and landscaping projects