Coir better than synthetics for making geo grids
COIR IS excellent for making the nettings or grids used on denuded hill-sides to fix soil and promote growth of vegetation, which, in turn, prevents landslides and improves the ecological balance in the area.
"Since coir is highly water-absorbant, ideal conditions are created for the germination of seeds", said P J Rao, an earth scientist at the Central Road Research Institute (CRRI) in New Delhi. CRRI scientists have been conducting experiments using coir geo-grids in different parts of the country since 1988.
"Unlike synthetics such as polyester and polyethylene, which are now being used to make the grids, coir is cheap, can be used round the year, needs little labour to manufacture and is biodegradable", said Rao. "Coir has a high lignin content -- 41 per cent as against 39 and 12 per cent in jute and cotton respectively. This makes it strong and resistant to rotting". Lignin is a complex, organic substance that makes plants rigid and woody.
Coir is more flexible than jute because of its physical and chemical structures. Placed on dry soil, jute loses its flexibility within six weeks but coir loses only 20 per cent of its flexibility over a full year. Near river embankments and seashores, coir fibre remains stable for upto 10 years, whereas jute lasts a bare year," said Rao. "Jute is just skin, but coir is both skin and muscle".
Nevertheless, though India is a major producer of coconuts, coir is yet to be used for making grids. Rao explained why, "There is always a gap between research and its application, mainly because of the government's unwillingness to try something new".