Analysts: labor-intensive Jatropha not a magic bullet

The oilseed plant Jatropha curcas is often touted as a biodiesel crop that can be grown on poor soils and requires relatively few inputs. However, analysts warn that this new 'underresearched' biofuel plant currently faces three major problems: yields are unreliable, seeds are toxic, requiring careful handling, and harvesting the nuts is extremely labor intensive.

Jatropha remains a wild plant that has not yet undergone the heavy agronomic, biotechnological and commercial research cycles so typical of the major oilseed crops that currently dominate the market. This is changing rapidly as biotech companies are investing in improving the crop (e.g. Bayer CropScience and D1Oils/BP).

However, the woody perennial shrub has attracted interest in countries like India and China because it can grow on barren, marginal land and does not intrude on farmland needed to grow food crops. Trial projects have shown that the crop can blend it with local farm practises as it is easy to maintain and requires few upfront costs and fertilizer and water inputs. So far, no major pests or diseases have been identified for Jatropha.

Labor intensive
However, M. R. Chandran, adviser to the Roundtable on Sustainable Palm Oil, today told an oil and fats conference that the crop is very labour-intensive as each fruit ripens at a different time. It needs to be harvested separately and manually.

In an earlier overview of labor inputs needed for different energy systems, Biopact too warned that Jatropha may be too labor intensive and would require very cheap labor to make economic sense. The labor intensity of biofuel production can be a benefit, as it implies the creation of a large number of jobs (see the renewable energy jobs calculator). But in order to be socially acceptable, the production system must also allow an increase in wages over time. Else, a situation akin to plantation slavery emerges in which laborers are kept in perpetual dependence, and the social potential of biofuel production evaporates.

In short, a balance must be found between labor intensity and the potential to take laborers along in an upward trend towards increased incomes. A crop like palm oil, also harvested manually, yields far more oil (energy) per man-hour, but still provides many jobs - a perfect balance (see table, click to enlarge).

Moreover, the very essence of an economic energy system is to produce as much energy as possible with as few energy and labor inputs as possible. Jatropha clearly faces a problem there:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: biodiesel :: Jatropha :: labor :: energy crops :: biotechnology ::

Toxicity
A second difficulty with Jatropha lies in the fact that its nuts and leaves are toxic. These toxic qualities have been exploited in traditional medicine across the developing world, where concoctions of Jatropha substances are used to heal wounds and treat a great variety of ailments (hence its popular name, the 'purging nut'). The plant can also be found in many West-African villages where it is used as a natural hedge to protect fields from grazing animals, who spontaneously stay away from the poisonous plant. But now that Jatropha production is being scaled up as a biofuel crop, the toxicity of the seeds may become a hazard for the people who have to harvest and process the seeds.

Research is needed to understand potential health risks for harvesters and handlers at the processing plants. An engineer specialising in oil and fat processing plants, including for biodiesel production, said special facilities were needed for crushing jatropha nuts as they could produce a toxic vapour. However, the same engineer, who declined to be named, is optimistic and said his company hoped to seal a deal with a private investor to build one of the world's first large-scale jatropha-based biodiesel plants in China's southern province of Yunnan before the end of this year.

Yields
Finally, so far Jatropha has not enjoyed much professional efforts to improve its productivity. According to analysts, it would take at least five years of intensive breeding and plant improvement before the crop could achieve productivity that would make its cultivation economically viable.

The oil yield of current wild species is less than 2 tonnes per hectare with large swings from year to year. Compare this with palm oil, yields of which are around three times as high, with continuous plant improvement research leading to varieties that yield ever more.


In short, jatropha still faces major difficulties to make it as an attractive biofuel crop. Some caution is required by potential investors who should not be blinded by the current hype surrounding the plant. On the other hand, most of these problems may be solved over the coming years. There is no reason to assume that the crop would be resistant to yield improvements. According to several sources, classic breeding techniques will possibly result in varieties with twice the productivity of wild plants. Modern biotechnology could develop genetically improved Jatropha, even though this would be controversial.

When it comes to the toxic nature of the seeds, several initiatives are already underway to turn this into a benefit: researchers hope to utilize the toxins in pharmaceutical applications (earlier post). Simple technical interventions and the establishment of safety procedures at seed crushing mills and biodiesel plants may offer solutions to the health risks that could emerge in the processing stage.

The labor question remains. However, Biopact knows that several organisations are currently researching mechanical harvesting techniques for Jatropha. They basically come down to systems that resemble olive harvesting machines ('tree-shakers'). It remains to be seen whether these techniques become viable, as jatropha continuously yields ripe nuts without there being any clear 'harvest' season.

References:
Reuters: Toxic jatropha not magic biofuel crop, experts warn - September 12, 2007.

Biopact: D1 Oils and BP to establish global joint venture to plant jatropha - June 29, 2007

Bipact: Interview: DaimlerChrysler, farmers see great future in jatropha - June 30, 2007

Biopact: Renewable energy jobs calculator - August 07, 2007

Biopact: Jobs per joule: how much employment does each energy sector generate? - September 01, 2006