Nitrogen-fixing trees the panacea
AREAS WHERE fly ash is dumped should be rehabilitated by planting suitable Nitrogen-fixing tree species, and serve as ?nutrient pumps?. A Forest Influence Officer at the Forest Research Institute (FRI) Dr Ramjee Srivastava told HT that the trees would be helpful in reducing the fly ash in nearby localities.india Updated: Apr 01, 2006 00:49 IST
AREAS WHERE fly ash is dumped should be rehabilitated by planting suitable Nitrogen-fixing tree species, and serve as ‘nutrient pumps’.
A Forest Influence Officer at the Forest Research Institute (FRI) Dr Ramjee Srivastava told HT that the trees would be helpful in reducing the fly ash in nearby localities.
The intangible benefits derived from afforestation of such areas included minimising problems of air pollution to society by providing vegetation cover, stabilisation of fly ash dumps and increasing the fertility and productivity of the wasteland and conserving the ecology of the environment.
Besides, the returns from sale of fuel wood, fuel grasses and timber
would provide fiscal benefits to inmates living around the thermal power plants.
Rehabilitation of such degraded areas would also improve the economic conditions of the affected persons, he said.
In order to explore the possibilities of reclamation and rehabilitation of fly ash areas through plantation, Dr Srivastava conducted a successful study at the Panki Thermal Power Plant in the city, in the early 90s and had planted certain
trees there to check pollution caused by fly ash.
After six years, it was found that environmental conditions improved considerably around the fly ash dump area and vegetation began showing.
During the study, Dr Srivastava found that fly ash was highly alkaline in nature and a good electricity conductor. It had poor water-holding capacity. It constituted of about 18 per cent coarse sand, 73.2 per cent fine sand, 7.3 per cent silt and 1.4 per cent clay. Fly ash had 7 per cent unburnt carbon, absence of Nitrogen essential for plant growth and it also lacked some essential micro-nutrients.
Taking into consideration the physico-chemical characteristics of fly ash, suitable treatment of fertile soil was given to the fly ash dumps and saplings of 10 selected species of plants were planted in the pits filled with normal fly ash.
Preliminary results showed that the four best performing species under treated as well as in untreated conditions were all nitrogen fixing. Besides over a half a dozen other grasses and herbs also appeared there.