Environmental Engineering Reference
In-Depth Information
plays a role in the socio-ecosystem, and its conversion to Jatropha production could
have economic, social, biodiversity and environmental impacts (Jingura 2011).
There are a number of interactions between Jatropha and the water resources at
any given site. Jatropha cultivation can have positive impacts with regard to water
resources, though these appear to be related to small-scale cultivation, particularly
as hedges, rather than at a plantation scale. It is postulated that small-scale Jatropha
projects can improve the water balance of a site, including more levelled flows in
rivers and streams, through increased evapotranspiration and erosion control, causing
a reduction of surface runoff and a higher infiltration capacity (Asselbergs et al. 2006;
Achten et al. 2007).
Additionally, however, there are several pressing concerns about the impacts of
large-scale Jatropha projects on the water balance of a site. Assessments have shown
that the yield of nuts per plant is much greater in irrigated plots than rain-fed plots.
This is due in large part to the fact that continuous irrigation determines the number
of fruiting periods per year (Ariza-Montobbio 2010a; 2010b). Jatropha plantations
therefore have a much higher water footprint than other crops like soybean, sugarcane
or maize (Achten et al. 2007). Bearing the importance of irrigation to higher yields
in mind, Jatropha could also bias larger-scale production with irrigation infrastruc-
ture over small and marginal farmers (Ariza-Montobbio et al. 2010a). Moreover, the
use of methanol in biodiesel production process presents further concerns about the
possibility of potable water pollution from large biodiesel production (Brittaine et al.
2010). Additional inquiry into the relationship between Jatropha and water resources
is therefore needed.
Impacts of Jatropha on Marginal and Forest Land Minimised
Both marginal land and forests can be important to rural farmers in developing coun-
tries, and Jatropha can have an impact on both. With regard to marginal or wasteland,
how land qualifies as idle, barren, under-utilised, unproductive, degraded, abandoned
or marginal is often politically charged and poorly defined despite the fact that these
terms refer to land that provides vital resources for poorer and more vulnerable groups
(Cotula et al. 2008; Ariza-Montobbio et al. 2010b). Common property resources
defined in this manner often supply important livelihood commodities such as food,
fuel, wood, fodder, timber and thatching material for homes and roofing (Rajagopal
2008). Yet the seizure of land from common property regimes is often done in spite
of insufficient data regarding the productivity of Jatropha under sub-optimal and
marginal conditions (Jongschaap et al. 2007).
Forest lands, like marginal lands, can also be negatively affected by Jatropha.
Forest cover has been replaced by other cash crops around the world. For instance,
palm oil, another biofuel plant, has resulted in the clearance of 18 million ha of primary
forest cover in Indonesia (Cotula et al. 2008). Although it is not yet clear what the
impacts of Jatropha on forests might be, it is unreasonable to assume that Jatropha
biofuels as an energy source will curtail deforestation. While the collection of firewood
results in forest degradation but not in large-scale deforestation (Openshaw 2000), it
is ironically agriculture in the vein and scale of Jatropha plantations that is responsible
for much tropical deforestation. Further assessments of the impact of Jatropha on
forests should also include a focus on changes in biodiversity.
Search WWH ::
Custom Search