Temps de lecture :3 minutes
[…] The issue of biofuels can generate disturbances as threatening as global warming, to which the development of plant diesel is supposed to be a response. But we must not throw the baby out with the bath water… The example of Jatropha should not be forgotten; it has many uses, including the production of an oil similar to diesel, which offers many disadvantaged countries significant growth prospects. For once, countries in semi-desert regions are at an advantage: Jatropha Curcas L. is a shrub that has demonstrated its value and grows without competing with food crops — quite the contrary…
Jatropha is a perennial plant which grows to a few meters and belongs to the Euphorbiaceae family. It is originally from Central America and today grows in all of the world’s semi-desert regions receiving between 600 and 1000 mm of rainfall per year, with long drought periods. It can be planted with seeds or cuttings.
The shrub is also called a physic nut. Women traditionally use all of its parts: the seeds, similar to the castor bean, are used as laxatives; the leaves are used for infusions against malaria; and the latex for healing and disinfecting wounds.
Animals, on the other hand, walk right past the plant because its seeds and leaves are not edible. This brings us to the Jatropha’s second asset: by planting it as a hedge around fields, it protects food crops against what is customarily called the “wandering of animals” in French-speaking Africa, meaning the roaming of sheep, goats, and donkeys from the village to salad beds or young sprouts of cotton or grain. This is not insignificant: in addition to preserving the crop in this way, disputes that often end in death between shepherds and farmers are avoided. Hedges also protect the soil against runoff during the rainy season as well as wind erosion.
Furthermore, the seeds (2 to 5 tons per hectare) contain approximately 30% high quality oil, which is mainly used to make a highly valued soap. The oil is also used to run local diesel engines: grain mills, oil presses, irrigation pumps, etc. It can also be burned in slightly adjusted oil lamps, or as kitchen fuel. Finally, press cakes, which are what remain after the pressing of the seeds, have a composition thought to be similar to chicken manure, making it an excellent organic fertilizer, precious for African soils.
For many years, non-governmental organizations have promoted this traditional cultivation. In Mali in particular and in other countries like Madagascar or Tanzania, the German Reinhard Henning is at the origin of research on the uses of Jatophra. He also led a GTZ project (a German cooperation) on twenty pilot sites in Mali, from 1993 to 1997. The concept of the “Jatropha System” stemmed from his experiences. He explains that the traditional cultivation of this shrub has four advantages:
• Promotion of women (soap production and sale of oil)
• Poverty reduction in the village (protection of crops, sale of grains, oil, soap)
• Erosion control (planting of hedges)
• Production of renewable energy for light, cooking, generator engines, mills, presses, etc.
According to Reinard Henning, the goal is not necessarily to start rampant planting of Jatropha on large areas, as is starting to be done in Egypt, for example. The idea is that in landlocked countries such as Mali with few public roads in decent shape, each village could be self-sufficient in terms of fuel production and lubricant. This need for autonomy is not insignificant since today fossil fuels reach villages at very high prices or in some cases not at all during the rainy season, when roads are flooded and impassable. What’s more, the soap produced provides women with an income. According to Mr. Henning, it is essential that women maintain control of this traditional activity in order to bring money into their community.
In any case, the Jatropha project has been highly successful in Mali. According to Reihard Henning, in 2002, there were 10,000 km of Jatropha hedges in the country (2 to 15 km per village on average), representing 1,700,000 liters of oil, with a growth rate of 2,000 km per year. Now the information just has to be spread to other Sahelian countries…
Is Jatropha the exception that proves the rule for biofuels, the good solution that unites the protection and even enrichment of food crops with renewable energy production?
Let’s hope so, for the countries concerned…
For more information
Using the Indigenous Knowledge of Jatropha, by Reinhard Henning, Indigenous Knowledge Notes No. 47, August 2002, World Bank
The Jatropha Manual- An Integrated Approach of Rural Development in Tropical & Subtropical Countries, by Reinhard Henning and Tianasoa Ramorafeno, available at www.jatropha.de
Jatropha Project- DNHE/GTZ- Production and use of plant oil as fuel, by Reinhard Henning, Oumou Sanakoua, and Yaya Sidibé. Bamako, Mali, 1996, available at www.jatropha.de
Jatropha – Not Just a Biofuel Crop! Developing Countries Farm Radio Network, Package 80, No. 7, March 2007. Available at www.farmradio.org/francais/