A Jatropha energy platform, installed by MFC in the village of Tabakoro, southern Mali, uses Jatropha as an alternative to diesel fuel in the single cylinder engine at its heart (left); soil collects around roots of jatropha hedges and plants, decreasing surface run-off, improving water absorption into the soil and improving soil fertility (left & right).
The planting of jatropha as a living hedge has only positive environmental effects, as it protects the soil from wind erosion. The roots of the plant bind the topsoil, so it is less vulnerable to the wind (responsible for 30% of soil degradation). When planted in hedges, the wind blows soil to accumulate at the base of the plants, forming boundaries along the ground. This holds in water, allowing more absorption of water into the soil and consequently less loss of soil carried away by surface runoff. The roots of the plants also break up the earth which can become compacted during the dry season, causing high surface runoff when the rains come. This again allows more infiltration of water into the soil. The production of good quality fertiliser as a by-product of oil production will also act to improve soils and agricultural production (small scale gardening).
As jatropha is inedible even by animals (except when the plants are seedlings), the jatropha hedges will also protect gardens from damage due to animals, which accounts for between 5 & 10 % of losses of produce.
As jatropha can flourish in the Sahel climate, surviving on less than 400mm rainfall per year and resistant to drought and pests, it has the potential to contribute to the fight against desertification. The soil protection properties and ease of propagation mean it is well suited to being planted on land that has been lost through deforestation or desertification.
Jatropha has also many comparative advantages over diesel in terms of the environment. The most obvious is that using jatropha oil as a fuel creates a closed CO2 cycle, i.e. when the oil is burned CO2 is given out into the atmosphere. But when the next crop of jatropha grows, it takes the CO2 back out of the atmosphere. Therefore there is no net release. With diesel combustion however, the CO2 that was locked up inside the fuel millions of years ago is released, but there is no absorption. So the jatropha helps to reduce the climate change.
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