Energy plantation is the practice of planting trees, purely for their use as fuel. Terrestrial biomass i.e.,
the wood plants has been used since long time to generate fire for cooking and other purposes. In recent years, to meet the demand of energy, plantation of energy plants has been re-emphasized. It is well known fact that trees have been intensively cut in Gangetic plains and coastal belts, leaving the area totally denude. The same practice has also been done in Shfwalik region and foot-hills of Himalayas.
According to a report, if fuel/fire wood plants were not raised rapidly, by 2,000 AD more than 250 millions people would not be able to manage fuels for cooking purpose and, therefore, they would be forced to burn animal dung which, however, depends on availability of animals and agricultural crop residues (Anonymous, 1980 c).
India is the biggest fuel wood producing country in the world, but the per capita fuel wood production is very low i.e.
/head. Mitchell (1979) estimated that the need of fire wood for cooking purpose in India is 0.8 kg per capita per day. But this value does not hold good for cold areas where firewood is also required for keeping houses warm.
In India, conditions of hills are quite different from that of plains. The villagers hardly get fire-wood plants, as they have to go in interior of forest and collect wood-falls. Even they have very limited right to fell trees and therefore, they depend on wood, falls and loppings of minor tree branches (Singh et al,
1988). If one talks about to meet their needs by making available technologies developed for plains, it is not feasible. For example, they cannot be motivated to use solar cooker, because of being solely traditional to which religious factors have been associated. Even gobar gas plant cannot be useful in hills, because of prevailing low temperature in mountain belt (Singh et al,
1988). Therefore, the search for renewable source of energy is highly desirable for survival of population in hills and for reducing the pressure on forests (Pant and Singh, 1987).
Recently, energy plantation has got much boost in our country. Government has started many plans, for example, social forestry, silviculture, agro-horticulture practices, and afforestation in waste lands. A large area of land is available in our country which is of no use. A total of 7 million hectares are usar.
The alkali soils found in U.P. are commonly known as usar
soils. They contain hard and compact surface layer with clay loam texture. Percentage of exchangeable sodium in these soils is more than 15%. The pH ranges between 8.5 to 10.5. Due to high amount of sodium, plant growth is badly inhibited.
Land is available in east, west and northern part of India of which 1.3 million hectare land exists in U.P. alone (Abrol et al,
1973). In addition, marginal lands in the form of long strips along railway lines, highways and other roads are also available.
Therefore, it has been realized that afforestation should be encouraged as much as agriculture along the coastal belts, Gangetic plains and in Himalayas. Singh and Singh (1987) studied the primary productivity of undisturbed forests in Central Himalayas located between 300-2,200 meter elevation. They noticed the primary productivity around 20 tonnes/ha/yr. According to them, the productivity of Central Himalayan Forests could be comparable with those of highly productive capacities of the world.
About 200 billion tonnes of carbon per year is fixed photosynthetically into the terrestrial and aquatic biomass. This amount of biomass contains 3,000 billion giga (109
) jules energy every year. It has been estimated that at present, only one seventh of the World's total energy comes from biomass and a large amount of it remains untapped.
In view of getting maximum biomass, afforestation and forest management systems will have to be developed. These must include social forestry, silviculture (short-rotation forestry) tree-use systems, coppicing system, drought, salt-, pollutant - resistant plantations and high density energy plantations (HDEP). HDEP is the practice of planting trees at close spacing. This leads to rapid growth of trees due to struggle for survival. It provides quick and high returns, and opportunities for permanent income and employment.
Therefore, annual plants should be grown to meet the demand of energy. Keeping in view the climatic and edaphic factors, plantation of deciduous trees should be encouraged, as their growth is faster than the coniferous ones. The species to be planted should have the following characters: (i)
fast growth, (ii)
stress resistance, (iii)
less palatable to cattle and other animals, (iv)
early propagable, (v)
high caloric value, (vi)
absence of deleterious volatiles when smokes come out, (vii)
high yield of biomass, and (viii)
Plantation through social forestry has been much emphasized by the Government of India to meet the demand of fuel and fodder in the rural areas. It will certainly decrease the gradually increasing pressure on the forests. This includes planting trees along road sides, canals, railway lines and waste lands in villages. Some of important plants are: Acacia nilotica, Albizia lebbek, A. procera, Anthocephalus chinensis, Azadirachta indica, Bauhinia variegata, Butea monosperma, Cassia fistula, Dalbergia sissoo, Eucalyptus globulus, E. citriodora, Ficus glomerata, Lagerstroemia speciosa, Madhuca indica, Morus alba, Populus ciliata, P. nigra, Terminalia arjuna, Toona ciliata, Salix alba and S. tetrasperma.
Silviculture Energy Farms (Short Rotation Forestry)
Silviculture energy farms employ techniques more similar to agriculture than forestry. The chief objective of energy plantation is to produce biomass from the selected trees and shrub species in the shortest possible time (generally 5-10 yrs) and at the minimal cost, so as to satisfy local energy needs in the decentralized manner. This would certainly relieve the pressure on the consumption of fossil fuel like kerosene and prevent the destruction of plant cover which is one of the primary components of the life support system (Khoshoo, 1988).
Advantages of Short Rotation Management
Jahn (1982) has discussed the following advantages from short rotation management from production of fuel biomass :
- High yield per unit of land area,
- Smaller land requirements for given biomass output,
- Shorter time span from initial stand establishment to harvestable crop,
- Increased labor efficiency through mechanization and other methods similar to those used in agriculture,
- Ability of most short rotation species to regenerate by coppicing; and
- Ability to take advantages of cultural and genetic advances quickly.
Therefore, production of plant-based renewable energy is a part of the dynamic agro-botany-forestry system and the need is to integrate both modern biology and culture in agriculture (Khoshoo, 1988, p. 356).