Friday, May 15, 2009

Jatropha: Biofuel Wonder Plant Fails to Deliver

by Kay Sexton

May 7th, 2009


Back in 2004/2005 a lot of publicity was given to Jatropha curcas. The ugly, dwarfish little tree with toxic seeds was proclaimed as the answer to the biofuel problem, because:
(a) it could be grown in marginal agricultural conditions and
(b) there was no other use for it, except firewood, so there weren’t competing claims on it as a resource.

All this added up to a wonder scenario: grow jatropha on the world’s drought-ridden impoverished soils so that it didn’t take up space otherwise used for corn and soya which both have dual use as food/biofuel resources, lock up carbon as the trees grew and then use their seeds to meet the global demand for fuel. Sounded too good to be true …and it was.
Local use good – global trading market bad

The central American tree does indeed grow in marginal lands, but when planted in poor soil, it produces poor seed crops, and that means that without agricultural inputs, the outputs are nothing like anybody had hoped. Despite the fact that China, Brazil, Burma and Malaysia have all invested in jatropha plantations in their poorer agricultural reasons, the return on their investment is looking highly limited.

Part of the problem is that the assessment made of the productivity of the tree necessarily used trees that had survived to maturity, rather than new plantation trees. This means that the inputs to the tree (fertiliser, rain or other water, mulch or other nutrients) may have varied over time and the trees that were measured may have been given much more support, whether by farmers or by nature, than was originally factored in to the equation. Much of the world’s drought-land has become highly impoverished over the past two or three decades but may have been richer in food and water for plants in the past.

This discovery leads to the same dilemma that emerges with all other biofuels – it becomes a food versus fuel debate about whether scarce resources should be used to support food crops or crops that can be sold to produce energy.
Burma fails to deliver on biofuel initiative

In Burma, the military junta ordered the population to plant jatropha, and as a result, plantations, rice paddies and even home gardens were dug up and turned over to jatropha, in part out of fear that failure to carry out the edict could lead to fines or maybe even imprisonment. But because there is no international market, nor an established infrastructure to mill and store the oil, much of the crop grown in Burma simply rots.

However, in India, a different approach might lead to a partial answer to the dilemma. Following the example of Mali, the Indian government intends to turn 27 million acres of marginal agricultural land over to jatropha, which will then be milled locally to make lamp oil and fuel for cooking stoves, as well as providing an easily portable fertiliser made from the remnants of the crushed seed, which can be used to enrich croplands as the toxicity inherent in the tree can be broken down by micro-organisms in the soil.

Researchers are trying to improve the yield of the crop, and because jatropha has a higher energy content per gallon than other biofuels, this could be part of the answer too. But both partial answers: community use and agricultural improvement, are long-term projects: jatropha, despite the hype, will not be a contributor to fuel security on the planet in the near, or even the middle future.

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