A new study has put the brakes on a rush by some countries and companies to establish plantations of jatropha, an oil-bearing shrub and cousin of the castor bean bush, as a source of biofuel.
The study by ActionAid, an anti-poverty NGO, the Royal Society for the Protection of Birds, and Nature Kenya, a conservation society, looked at whether biofuel made from jatropha grown in the Dakatcha woodlands in Kenya’s coastal district of Malindi, could indeed be a green fuel.
Chris Coxon of ActionAid said the oil yield of the seed from plants grown on land earmarked for jatropha cultivation in Malindi would determine whether the shrub provided a viable alternative to fossil fuel.
Previous land use was another critical factor. The study found that throughout the production and consumption process in the Dakatcha woodlands, the jatropha would emit between 2.5 and six times more greenhouse gases than fossil fuels, largely because of clearing the forest, which stores massive amounts of carbon in its vegetation and soil, to make room for the plant.
Other studies have also found that the yield from jatropha can vary considerably, because contrary to the popular perception that it can thrive in semi-arid conditions, the plants need water and nutrients to produce high yields.
So, if an investment in irrigation and fertilizer is required, why not grow food crops instead, the study argued. Much of the biofuel from the Dakatcha woodlands project, when it starts producing, is destined for Europe to meet regional targets for switching to renewable energy.
The study underlined what a joint UN Food and Agriculture Organization (FAO) and International Fund for Agricultural Development (IFAD) report on jatropha had found in 2010 - that the shrub was useful as a bio-energy crop for cultivation by small-scale farmers.
"Some communities in the dry sahel of Africa have told us they are not against jatropha, only large plantations established by foreign companies for export without their consent," said Tim Rice, ActionAid's biofuels expert.
"They proposed growing small plots of jatropha on their own agriculural land or as a 'hedge' to divide fields. Used locally, it could be used as fuel for stoves, irrigation pumps and generators."
But even then, growing jatropha could prove uneconomical if there was no investment in developing higher oil-yielding, non-toxic varieties.
The Kenyan government has suspended clearing the full 50,000 hectares of forest, which would have displaced 20,000 people for the proposed plantation in Dakatcha, pending an environmental impact assessment, the study said.
“What concerns us is the growing move towards massive plantations of jatropha in developing countries,” said Coxon.
Here is a closer look at jatropha and why it has caught the imagination of so many.
In 2008, jatropha was planted on an estimated 900,000 hectares globally; 760,000 hectares (85 percent of the total) were located in Asia, followed by Africa with 120,000 hectares and Latin America with 20,000 hectares. By 2015, jatropha would be planted on a projected 12.8 million hectares, according to an FAO report.
By comparison, maize, one of the world’s major staple grain crops, is planted on more than 160 million hectares.
In another four years, Indonesia will be the largest jatropha producing country in Asia. In Africa, Ghana and Madagascar will be the biggest producers, while Brazil will be the main producer in Latin America.
Jatropha has a long history of being recognized as a substitute for fossil fuel. During the Second World War it was used as a replacement for diesel in Madagascar, Benin and Cape Verde, while its glycerine by-product was used to make nitro-glycerine, used in explosives and medicines for treating heart conditions.
FAO said jatropha had gained some ground as a source of oil for producing biodiesel because of the common perception that it could be grown in semi-arid regions with low nutrient requirements and little care.
Jatropha's extensive roots allow it to reach water deeper in the soil and extract leached mineral nutrients unavailable to many other plants. The surface roots also help bind the soil and can reduce erosion. Compared to other biofuel crops such as sugarcane, it requires less water.
It is a non-edible crop, “So the biodiesel sector does not compete with food and feed use of this crop,” said Simla Tokgoz, a researcher at the International Food Policy Research Institute (IFPRI), a US-based think-tank. Other feedstocks used in biodiesel production are rapeseed, soybean, coconut, and palm.
Jatropha is still in the early stages of development as a biofuel but is expected to be a less expensive source for biodiesel production, which could increase profitability, Tokgoz said.
Jatropha oil can be used directly in some diesel engines without being converted into biodiesel, but because it has a higher viscosity than mineral diesel, it works better in tropical environments, where temperatures are higher.
Is it a viable alternative?
Large-scale biodiesel production will need more water, and in water-stressed conditions this could lead to conflict. The FAO/IFAD report said jatropha biodiesel conformed to the required European and USA quality standards, but cautioned that "It is not a technology suited to resource-poor communities in developing countries."
Biodiesel production also requires expertise, equipment, and the ability to handle large quantities of dangerous chemicals such as toxic methanol and highly corrosive sodium hydroxide.
When comparisons are made of the return on labour input Jatropha performs poorly against other biofuel feedstocks, but much depends on the level of yields, which need to be improved, the FAO/IFAD report said.
Jatropha has a marketable non-edible by-product, but it is less valuable than canola, for example, which can be consumed by animals, said Tokgoz.
Instead of competing for agricultural land, or removing forests or displacing communities, Tokgoz suggested planting government wasteland or contract farming using small- and medium-scale farmers. But again, this would mean investment in irrigation, inputs and efforts to improve yields.
Jatropha is regarded by many as an invasive plant and has been declared a noxious weed in parts of Australia, FAO pointed out. South Africa has banned its commercial production.