The use of natural fibers for erosion and sedimentation control dates back to the beginning of this century. The main problems in the early natural fiber textiles (example jute mats) were low tensile strength, high elongation and low durability. These drawbacks restricted their use to only less severe erosion problems. An alternate natural fiber that has drawn the attention of the erosion and sedimentation control industry is coir, the coconut fiber.
One of the most effective and yet natural soil erosion prevention techniques is the use of coir geotextiles (coir netting) fabrics. CoirGreen geotextiles have no synthetic material but are instead made out of organic fiber coir, which is extracted from the husk of a coconut. Coir is strong, durable, waterproof and one of the few natural fibers that is salt water resistant.
The lighter varieties of coir woven geotextiles are used for immediate soil erosion and ordinary soil conditions while the heavier coir geotextiles are used for embankments, slopes or vegetation. CoirGreen geotextiles protect the soil until the vegetation permanently covers its mesh. It gives the plants adequate room to grow and decomposes naturally into humus which will enrich and nourish the soil. Lasting between two to five years the coir fiber, compared to other natural fibers such as jute, has several unique features. CoirGreen geotextiles have the ability to retain water three times more than its actual weight preventing the need to frequently water the plants. However, at the same time with its adequate space within the mesh it drains the excess water easily preventing water logging. With an easy installation method the CoirGreen geotextiles need no chemical treatment as it lets in the right amount of air and light for a deeper rooted plant. It can also endure animal and human movements that would generally lead to more environmental decay.
“Recognition of coir for sustainable vegetation and erosion control arises from the fact that it is an abundant, renewable natural resource with an extremely low decomposition rate and high strength compared to other natural fibers. Coir is woven into thick textiles which are applied like blankets on the ground in erosion prone areas. Geotextiles made from coir are durable, absorb water, resist sunlight, facilitate seed germination, and are 100% biodegradable. These blankets have high strength retention and a slow rate of degradation meaning they last for several years in field applications”.
Studies conducted have proven that coir geotextiles are effective, inexpensive and environmentally friendly. In one study conducted in 1998 on coir geo textiles, Schuerholz found out that coir retained 20% of its strength a year later and 90% humidity whereas jute biodegraded fully after eight weeks. In another study, conducted in Kerala, India, with a farmer community in 2005, scientists found out that coir combined with local grass prevents soil erosion.
The uses of CoirGreen geotextiles can be summarized as below,
- Stream/River bank protection
- Shoreline stabilization
- Slope stabilization in railway cutting and embankments
- Separation application in rural roads, railways, parking and storage areas and storm shuttering
- Reinforcement of rural unpaved roads, temporary walls providing sub base layers in road pavements
- Filtration in road drains and land reclamation
- Containment of soil and concrete as temporary seeding
- Concrete column curing
- Waste protection and forestry re-vegetation
- Control of shallow mass waste and gully erosion
- UV protection for underground crops
- Rooftop landscaping
- Protection from wind erosion and wetland environments
- Plant and tree protective systems