This is a well written article on the possibilities of jatropha culture in Africa in particular. They do not talk about oil yield per acre and temperature sensitivity is also not addressed. A quick check informs us that yields are likely comparable to that of other oil seeds, but with real potential for breeding success to produce much higher yields. It is still a tree after all and has superior capacity against an annual that put its energy into its maturation cycle. The plant prospers in semi tropical and will not stand up to a hard freeze.

Again, all effort is presently focused on established fields. However, this is an ideal plant for exploiting agriculturally marginal slopes and soils. It is practical for a family farming a couple of hectares of valley bottom to cover the surrounding hillsides with jatropha. It ability to prosper in semi arid environments is key to this form of husbandry and we ultimately reestablish rooted soil systems and perhaps more valuable trees years later.

This is also a valuable tool to replace the deforestation caused by endemic charcoal manufacture.

It has become utterly critical that the subject of land tenure and land tenure statute responsibility be properly addressed globally and locally in order to direct human resources onto lands currently not exploited at all. Competing for a scrap of all purpose bottom land is bone headed when large swathes of hillside are begging to be properly managed with crops such as this.

A combination of subsidy, regulation and floor price management with a viable land tenure regime can revolutionize global agriculture and massively expand the human opportunities. Instead, it is usually managed by fractious bone headed fools who insist in changing nothing or taking bribes.

Humble tree offers Africa a greener future


A humble, hardy tree called the jatropha may hold the key to providing Africa with cheaper, cleaner energy and pulling millions of rural poor out of the poverty trap. That is the vision of southern African green activists, who are promoting innovative projects at the Earth Summit here to use the trees oil-bearing seeds for fuel to power trucks and light homes.

"Biofuel has a great future, but only so long as governments legislate to encourage its use," said Jarrod Cronje of Africa Eco Foundation, a South African non-governmental organization promoting its initiative at the Earth Summit in Johannesburg.

Finding a renewable alternative to conventional diesel is an idea that dates back to the 1930s. Oleaginous crops such as rapeseed, also known as colza, are a favoured source in the northern hemisphere. But in the harsher, drier conditions of Africa, a more resilient source is needed.

The best candidate is Jatropha curcus, a tree that was introduced into Africa several hundred years ago, so there is none of the ecological risk which comes from introducing a new species, and which is already being successfully grown and harvested as a biofuel in Nicaragua.

The jatropha, also called the physic nut, grows quickly and needs little water or nurturing, reaching maturity after two years, and yielding small black seeds that are covered in light, white husks and which can be picked by hand. It grows to about the size of an apple tree, which means that harvesting does not require tall ladders.

The seeds are then crushed to extract raw oil, a process that also provides organic fertilizer from the husks. A simple and cheap chemical, caustic soda, is added, which separates the oil into liquid soap, which is siphoned off, and a more refined oil.

That substance is then heat-treated with methanol, which in turn yields a glycerol sediment, which is a cosmetic ingredient, and also diesel, which can be used like its fossil-fuel counterpart in trucks, buses and generators.

"Jatropha biodiesel is a little bit cleaner than conventional diesel. There are no sulphur emissions," said Cronje. It still produces carbon dioxide, the greenhouse gas that drives global warming, but by growing trees, which soak up CO2, the environmental damage would be far less than from conventional fuel.

Africa Eco Foundation calculates that jatrophas and another oilseed tree called the maringa could be commercially viable on plantations of 1,000 hectares (2,400 acres), which would have a cheap tunnel-shaped greenhouse made from plastic film to grow seedlings.

A family of four to six people could prosper if it had a 25-hectare (75-acre) section, earning a net profit of between 2,000 and 4,000 randto 400 dollars, euros) a month, which is several times the typical income in rural South Africa. Families could also supplement their income from honey, placing beehives near the trees.

To get the ball rolling, Africa Eco Foundation is pitching for funds from the World Bank and local authorities.

In Zimbabwe, meanwhile, a group called Environment Africa is selling jatropha soap and has discovered that the raw oil can be burned in a specially-adapted lamp, which is a boon for people living in remote villages where there is no electricity.

"Its like using paraffin," said Environment Africas executive director, Charlene Hewat. Interest in biofuels surged after the 1970s oil shocks, but fell back when the oil price fell.

Today, though, many countries around the world have passed laws requiring diesel to contain a minimum percentage of biofuels. The best record is held by the Czech Republic, which insists on 100-percent biofuel content.

A small jatropha biofuel project has been launched in Mali, in west Africa, with German help, but none exists so far in the south of the continent.

All rights reserved. © 2002 Agence France-Presse.

No comments:

Post a Comment