Jatropha curcas: from Global Hype to Local Solution

Trabucco A., Achten W., Aerts R., Van Orshoven J., Mathijs E., Muys B.

Jatropha: Basic Facts

Jatropha Potentials:

• Small tree (5-7 meters), originary from Central America.

• Non-food crop, unlike most of biofuels.

• Biofuel easily extractable from seeds with mechanic press.

• Adapted to semiarid conditions and suited for marginal land.

The Mith:

• Adapted to very arid conditions (as low as 300 mm of annual precipitation)

• Very high seed productivity (as high as 20,000 kg of dry seeds per ha per year)

Jatropha: The Hype

The Building of a Hype:

• Concern about fossil fuels price, reserves and sustainability.

• Sudden interest for Jatropha, as optimal biofuel solution.

• Jatropha remains still a mysterious plant with agro-climatic properties still unclear.

• Over optimistic expectations for productivity and suitability in arid conditions.

• Large and rapid investements from public and private sectors on Jatropha plantations based on disappointing expectations.

Jatropha: Productivity Assessment

Lack of Productivity Assesment:

• Traditional methods to evaluate land suitability and crop productivity use agroclimatic knowledge still not available for Jatropha.

Implementation of a Novel Method to Assess Jatropha Productivity:

• Given the impellent need of agroclimatic knowledge to assist Jatropha economic interests, we implemented a novel method relating biophysical factors to seed productivity through fitness metrics (Maximum Entropy approach, Philips et al 2006).

• Significant accuracy evaluation from seed yield measurements (r2 = 0.62) and positive expert evaluation.

Jatropha Seed Productivity Map

• Jatropha follows largely a pan‐tropical distribution, favoring areas with a dry season.

• Suitable areas are observed in warm temperate climates with enough rainfall, a drought 

period and no frost risk.

Jatropha Productivity

Average productivity for Köppen climate classes

Köppen Classification Average Productivity 

(kg dry seeds ha‐1 yr‐1)

TROPICAL

Fully Humid 1150

With strong monsoon and short dry season 2200

With strong dry season > 60 mm 2300

TEMPERATE 

Subtropical desert with average temperature > 18 °C 750

At least 10 times as much precipitation in wettest period as in driest period and 

average temperature of warmest quarter > 22°C1950

Without dry season and average temperature of warmest quarter 

Jatropha Productivity and Land Uses at Global Scale (Level I)

Existing Land Use Type Area (km2)Average

Production (kg Seeds / ha * yr)

Oil Production (Millions of barrels / yr)

% of Global yearly Oil

Consumption (2006-2007)

CroplandPost-flooding or irrigated croplands (or aquatic) 735,534 1893 219 0.70

Rainfed croplands 1,578,312 1903 472 1.52

Mosaic cropland (50-70%) / vegetation (grassland/shrubland/forest) (20-50%) 1,804,154 1926 546 1.76

Mosaic vegetation (grassland/shrubland/forest) (50-70%) / cropland (20-50%) 2,030,997 1909 610 1.96

Total Cropland 1,847 5.95

"Marginal"Natural and Semi-natural Terrestrial Vegetation – Shrubs 3,532,781 1984 1,102 3.55

Natural and Semi-natural Terrestrial Vegetation – Herbaceous 524,133 1894 156 0.50

Natural and Semi-natural Terrestrial Vegetation - Sparse Vegetation 140,569 1023 23 0.07

Bare Areas 50,310 1244 10 0.03

Total “Marginal” 1,291 4.16

Forest 5,169,883 2059 1,673 5.39

Jatropha Results aggregated for land use types (JRC, year 2006):•Sub-humid and semi-arid conditions (annual precipitation < 1500 mm)

•Excluding protected areas

•Economic viability (Seed productivity > 500 kg dry seed per year per ha)

Jatropha Productivity and Land Uses at Global Scale (Level I)

• If all the marginal land was converted (4,000,000 km sq), only about 4% of the total global oil consumption would be fulfilled.

• Most of marginal land is associated with shrubs (significant level of carbon stocks).

• Under global demand for oil, mixed croplands and forests can easily become target for Jatropha exploitation, where economic viable.

• Our study showed that Jatropha productivity might decrease on average because of climate changes.

Jatropha Productivity and Land Uses at Country Scale (Level II)

• Several differences arise on land use opportunities at country scale.• Jatropha produced on marginal land can cover substantially oil demand of several

countries.

Jatropha Productivity and Land Uses at Country Scale (Level II)

• Several differences arise on land use opportunities at country scale.• Jatropha produced on marginal land can cover substantially oil demand of several

countries.

Jatropha Productivity and Land Uses at Country Scale (Level II)

• Different levels of sustainabile use of Jatropha are found as we move from global to

country scale.

• Existing policies promoting Jatropha at country level sometimes in contrast with real

potentials of Jatropha and optimal land use availability.

• Discussion on biofuels sustainability, at least for the case of Jatropha, should be

articulated both on country level and global.

• Big differences exist also because oil demand per person varies developing and

developed countries.

Jatropha Productivity and Land Uses at Community Scale (Level III)

For population density (persons per square km) > 10 and < 1000 and within a 10 X 10 km block

(assumed as instance of community scale), we calculated where:

Jatropha biofuel production from marginal land > oil consumption per capita x number of people

Jatropha Productivity and Land Uses at Community Scale (Level III)

For population density (persons per square km) > 10 and < 1000 and within a 10 X 10 km block

(assumed as instance of community scale), we calculated where:

Jatropha biofuel production from marginal land > oil consumption per capita x number of people

Jatropha Productivity and Land Uses at Community Scale (Level III)

• Opportunity for Jatropha as biofuel fulfilling energy demands for marginal communities in Africa.

• Low levels of oil consumption per person is present in Africa, unlike for the rest of the world.

Jatropha Productivity and Land Uses:Discussion

• At global scale the high demand for oil could force large land use changes, otherwise engaged

with food production and carbon stocks.

• Suitability of Jatropha to provide sustainable energy supply changes at different scales.

• At smaller scales different opportunities for sustainable use of Jatropha are more evident.

• Yet, is unrealistic to conceive local and country economies unsensitive to the global market.

• The crash of the Jatropha hype can become an opportunity for more sustainabile adoption of

Jatropha as a partial energy solution.