Journal of Sustainable Bioenergy Systems, 2012, 2, 37-42
http://dx.doi.org/10.4236/jsbs.2012.23006 Published Online September 2012 (http://www.SciRP.org/journal/jsbs)
Assessing the Availability of Land and Water Resources for
Production of Energy Crops in Southern Africa
Kelebogile B. Mfundisi
Land Management Department, Polytechnic of Namibia, Windhoek, Namibia
Email: kmfundisi@daad-alumni.de, kmfundisi@polytechnic.edu.na
Received July 7, 2012; revised August 7, 2012; accepted August 20, 2012
ABSTRACT
Production of energy crops is perceived as a potential source of alternative energy for petroleum oil. However, it is cru-
cial to ensure that there is adequate land and water available for production of energy crops before indulging into the
business of producing such crops. This p aper assesses the availability of land and water resources for production of en-
ergy crops in the SADC region using landuse/landcover data, hydrological and meteorological data, as well as socio-
economic data. It is found that Botswana and Mozambique have large amounts of bushland that can be used for expan-
sion of agricultural land including production of energy crops. Zimbabwe has the highest amount of land under cultiva-
tion, which makes it difficult for the country to expand its agricultural land. However, land reform processes taking
place in Zimbabwe provides a good opportunity to diversify agricultural production including reallocation of farms for
production of energy crops. Mozambique has favorable rainfall for production of maize and sugarcane, whereas Zim-
babwe can explore growing Jatropha on degraded land and use irrigation for cultivation of sugarcane. High frequency
of crop failure in Botswana makes it difficult to grow maize or sugarcane as energy crop. The country can promote
production of sweet sorghum, which is traditionally grown by small scale farmers, and explore production of Jatropha
in degraded and desert land. A regional approach to address land and water requirements for production of energy crops
is considered important as compared to planning for production in each country as the constraints and potential of each
country can be fully recognized. More detailed country specific research is needed on the production of the specified
energy crops to ensure sustainab ility of the production systems.
Keywords: Energy Crops; Fossil Fuels; Landuse/Landcover; Regional Approach; Water Resources
1. Introduction
Affordable energy services are among the essential in-
gredients of economic development [1]. This could help
in eradication of extreme poverty and ensuring environ-
mental sustainability in developing countries as called for
by the United Nations Millennium Development Goals.
Meeting these essential energy needs economically and
sustainably requires a balanced energy portfolio that is
suited to the economic, social, and resource conditio ns of
individual countries and regions [2]. Currently, the major
source of energy for world economies is petroleum oil,
which has become expensive over the last three decades
[3]. Although oil importing African countries recorded
positive overall GDP growth in the past few years, there
are mounting internal and external imbalances. Mount-
ing budget deficits and inflationary pressure in oil im-
porting African countries disproportionately affect the
poor because of lower employment prospects and lack of
safety nets [4]. Additionally, petroleum oil is a major
source of carbond ioxide, a greenhouse g as of global con -
cern in climate change debates [5]. Therefore, an a lterna-
tive source of energy such as bioenergy produced from
energy crops provides an affordable option for develop-
ing countries, especially those in Africa where its poten-
tial has not been fully explored. Energy crops are a source
of renewable energy with reduced green house gas emis-
sions as compared to fossil fuels. Countries in southern
Africa are buying into the idea of producing energy crops
due to both international pressures and the increased en-
ergy dem a n ds within them.
Bioenergy is energy produced from organic matter or
biomass [3,5]. This can be in the form of bioethanol or
biodiesel. Bioethanol is fuel from distilled fermented
sugars and starches, and biodiesel is methyl or ethyl
ester of fatty acids made from virgin or used vegetable
oils [5,6]. For example, Jatropha curcus is a large fast-
growing, drought resistant perennial shrub that grows in
tropical countries mainly in hedgerows. The seeds yield
for Jatropha ranges from 0.5 - 12 tones/ha/year depend-
ing on soils, nutrient and rainfall conditions [7]. It can
yield up to 2700 kilograms of raw oil per hectare. Pro-
jects to demonstrate the possibilities of producing bio-
C
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K. B. MFUNDISI
38
diesel from Jatropha have started in South Africa, Ma-
lawi, Lesotho, Swaziland and Zambia. Other countries in
the region are also at a planning stage to embark on bio-
energy production projects. However, large scale produc-
tion of energy crops requires land and water resources.
Setting aside land and water resources for production of
energy crops is a challenge for developing countries that
are also struggling to meet their food security needs
and maintain ecosystems productivity. Even developing
countries that have relatively high GDPs like Botswana
depend on imports to meet their food security needs, and
the remaining ecosystems service a lucrative wildlife
based tourism industry. The two main challenges faced
by these countries are: how to set aside land for produc-
tion of energy crops without infringing into land avail-
able for food production and conservation of natural re-
sources, and how to ensure that there is adequate source
of water required for production of energy crops as well
as that needed to sustain ecosystem productivity.
Southern Africa is comprised of countries that vary
in terms of landuse/landcover, hydro-meteorological and
socioeconomic aspects. This research assesses the avail-
ability of land and water resources for production of
energy crops using landcover/landuse, hydro-meteoro-
logical and socioeconomic data for the SADC region
(Figure 1) with particular focus on Botswana, Mozam-
bique and Zimbabwe. The potential energy crops already
grown in some countries in the SADC region are Jatro-
pha, sugar cane, maize, and sweet sorghum. Jatropha is
especially suitable for degraded land and is drought re-
sistant. Maize can grow in all the selected countries and
sugarcane grows well in Zimbabwe and Mozambique,
whereas sweet sorghum is commonly grown in Botswana
albeit not for energy production.
Figure 1. Map showing countries in the SADC region.
2. Materials and Methodology
The research was carried out using secondary data on
landcover/landuse, hydrometeorology and energy con-
sumption patterns for the SADC countries. Three coun-
tries were selected based on their energy consumption
patterns and greenhouse gas emission trends. These were:
Botswana, Mozambique and Zimbabwe, which had least,
moderate and high carbondioxide emissions from con-
sumption of petroleum products respectively. The land-
cover data for Zimbabwe and Mozambique was pro-
vid ed by the Southern African Development Community
(SADC) office in Gaborone, whereas that for Botswana
was provided by the Botswana Ministry of Agriculture.
All the data on hydrometeorol ogy was provided by SADC.
And data on energy trends was downloaded from the US
Energy Inform at i on Administrat i on websi t e [8].
2.1. Landcover Area Estimation
Knowledge of landcover is important for many planning
and management activities concerned with the surface of
the earth. This involves the use of panchromatic, medium
scale aerial photos to map landcover. More recently,
small scale aerial photographs and satellite images are
utilized for mapping land cover of large areas. Landcover
refers to the type of feature present on the surface of the
earth [9]. The landcover shapefiles for this study were
obtained from SADC office in Gaborone, Botswana. The
data was processed using ArcView geographic informa-
tion systems (GIS) tools to extract the information on
different landcover types. Area covered by each land-
cover type was then used to estimate their percentage
cover. The landcover types selected for this research
were: cultivated area, bush land, b areground, forest. Bare-
ground is regarded to be synonymous to degraded land
for the purpose of this study. Land degradation includes
loss of vegetation cover [10], which in this case is con-
sidered to be bareground. Soils that are of rather poor
quality such as those in the Kalahari Desert of Botswana
fall within another category of degraded land.
2.2. Hydro-Meteorological Data Processing
Hydro-meteoro logical data for the years 199 6-2006 were
obtained in spatial form and ArcView GIS was used to
process it to show rainfall distribution patterns over the
whole of SADC. Seasonal rainfall data was used to esti-
mate rainfall distribution over the SADC countries at the
start and end of th e growing season. The growing season
does not start at the same time with the rainfall season.
The former is the time when crops are already accumu-
lating biomass, whereas the later is the initial period
when rainfall start and soil moisture accumulates before
seeds can be sown. Since each country in SADC differs
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K. B. MFUNDISI 39
in terms of the timing of pr ecipitation events, the focus of
this study is on the growing season, which on average is
from January to March. Simple statistical analysis such
as mean values and medians were used to select places
with suitable rainfall for production of energy crops us-
ing yearly data from January to March.
Water Requirement Satisfaction Index (WRSI) for the
region was filtered using median value of all the coun-
tries to show places with moderate values. WRSI is a
measure of the extent to which the water requirement of
a particular crop has been satisfied during the growing
season [11]. All the places with WRSI above the median
value were selected and their spatial distribution dis-
played on a map. Maize was used as a reference plant
because it is comparable with water requirements for
sweet sorghum. It has water use efficiency (WUE) of 370
kg water/kg dry mater, and sweet sorghum is 310 kg wa-
ter/kg dry mater [12]. Sugarcane has 4 times water re-
quirement as sweet sorghum, and Jatropha curcus has
the least water requirement among all the energy crops.
3. Results and Discussion
3.1. Greenhouse Gas Emissions from Petroleum
The results from analyzing energy data shows that there
is increased greenhouse gas emissions from consumption
of petroleum oil in the SADC Countries (Figure 2).
Zimbabwe is among the countries in Southern Africa
with high emission rates, Mozambique is moderate and
Botswana has the least emission rates. Therefore the
three countries form a good representative site for as-
sessing the possibility of producing bioenergy crops for
both reduction of greenhouse gases and carbon credits.
Figure 2. Carbon dioxide emissions from petroleum con-
sumption (1980-2005).
3.2. Landcover/Landuse
Tables 1-3 show total area covered by the different
landcover types in Botswana, Mozambique and Zim-
babwe respectively.
In Zimbabwe a large area of land is used for cultiva-
tion. It is not known wh ether the land is still used for the
intended purpose because of the land reform processes
going on in the country. Generally, Biofuels require ad-
ditional land [13]. Mozambique and Botswana have high
percentages of l and under bus hla n d.
In addition, there is presence of degraded land in Mo-
zambique and Zimbabwe that is suitable for growing J.
curcus. The percentage of land used for cultivation in
Mozambique is relatively low as compared to the
neighboring Zimbabwe. The bushland in Mozambique
provide an opportunity to expand agricultural land in the
country. This expansion could include land for produc-
tion of energy crops. Botswana has the least amount of
area under cultivation and a large piece of land is bush-
land. The bushland in Botswana occurs in areas with
poor sandy soils not suitable for agricultural production
resulting in limitation on expansion of agricultural land.
The presence of bareground in Botswana is not included
here, as it is difficult to determine it because the Kalahari
Desert sand covers a large portion (two thirds) of the
Table 1. Area covered by different landcover/landuse types
in Botswana.
Landcover Type Total Area (km2) % Total Land
Cultivation 800 0.1
Bushland 197,665 34
Bareground - -
Forest 6297 1.1
Table 2. Area covered by different landcover/landuse types
in Mozambique.
Landcover Type Total Area (km2) % Total Land
Cultivation 47942.18 6.1
Bushland 179233.53 22.8
Bareground 6341.58 0.8
Forest 464.06 0.06
Table 3. Area covered by different landcover/landuse types
in Zimbabwe.
Landcover Type Total Area (km2) % Total Land
Cultivation 107049.59 27.5
Bushland 48906.38 12.6
Bareground 1006.64 0.3
Forest 107.84 0.03
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K. B. MFUNDISI
40
country [14]. A feasibility study for production and use
of biofuels in Botswana indicates that rainfall and soil
conditions in the country are suitable for production of
sweet sorghum and J. curcus [15]. Therefore, the bush-
land in Botswana is available for production of the crops.
Farmers in Botswana traditionally grow sweet sorghum
albeit not for production of en ergy. This makes it easy to
promote sweet sorghum as compared to J. curcus, be-
cause little information is available to farmers about
production of the later.
3.3. Hydro-Meteorological Data
Figures 3(a) and (b) show a trend in average rainfall
distribution over the SADC countries for the beginning
and end of the growing season in January and March
respectively, from 2000 to 2005. Once in six years Bot-
swana experienced average rainfall of 51 - 100 mm in
the beginning of the growing season. Average rainfall
above 50 mm in a month is adequate for crop biomass
accumulation. This is particularly true for maize and
sweetsorghum, which do not differ much in their water
requirement and are known to perform well under such
rainfall amounts. Rainfall above 100 mm in a month
normally results in flooding conditions that are not fa-
vourable for the two crops but are particularly good for
production of sugarcane. In agricultural production the
spatio-temporal distribution of rainfall is important as
compared to cumulative amounts. The spatio-temporal
rainfall distribution can be used to determine the per-
formance of crops over the growing season and ulti-
mately the potential yield. Mozambique always had
rainfall ab ove 51 mm throughou t the six years, and Zim-
babwe had 2 in six years average rainfall of more than 51
mm for the month of January. For the end of the growing
season Botswana had once again one in six years average
rainfall more than 51 mm. Zimbabwe had 2 in 6 years
average rainfall over 51 mm, and Mozambique had more
than half of the time average rainfall above 51 mm. Mo-
zambique has enough moisture for growth of crops in the
beginning of the growing season 100% of the time and
more than 50% of the time the crops have enough mois-
ture during the end of the growing season. Energy crops
such as sugarcane and maize grow well under the rainfall
conditions in Mozambique. The situation in Zimbabwe is
also relatively better suitable for crop production as
compared to Botswana as irrigation could be used to
supplement rainfall. However, drought resistant crops
such as Jatropha can be tried in Botswana. Also sweet
sorghum survives under less rainfall conditions found in
Botswana though it is currently not used as an energy
crop. Its potential as an energy crop in Botswana should
be explored.
The results from estimation of water requirement satis-
faction index (Figure 4), using maize as a reference crop,
also agree with those from the seasonal rainfall distribu-
tion. Botswana has a high percentage of crop failure over
the whole country as compared to Mozambique and Zim-
babwe. The northern portion of Mozambique is good for
crop production as it has less amount of crop failure. This
result is only applicab le to the growing seaso n of the year
(a)
(b)
Figure 3. (a) Trends in average rainfall for the beginning of
the growing season in SADC countries; (b) Trends in aver-
age rainfall for the end of the growing season in SADC
countries.
Copyright © 2012 SciRes. JSBS
K. B. MFUNDISI
Copyright © 2012 SciRes. JSBS
41
Figure 4. Maize water requirement satisfaction index (WRSI) for SADC countries.
[3] UN Energy, “Sustainable Bioenergy: A Framework for
Decision Makers,” 2007.
http://esa.un.org/un-energy/Publications.htm
in southern Africa, i.e. January to March. Therefore, does
not apply to other periods of the year.
4. Conclusion [4] United Nations Economic Commission for Africa, “Eco-
nomic Report on Africa 2007. Recent Economic Per-
formance in Africa and Prospects for 2007,” 2007.
http://www.uneca.org/era2007
The research has revealed that Mozambique has a high
amount of land available for production of energy crops.
Favorable rainfall conditions in Mozambique are suitable
for production of sugarcane and maize as energy crops.
Zimbabwe can explore using degraded land for produc-
tion of Jatropha. And Botswana has to explore growing
sweet sorghum as an energy crop as well as jatropha.
Farmers in Botswana are already growing sweet sorghum,
which makes it easy to promote it as a potential energy
crop.
[5] A. K. Agarwal, “Biofuels (Alcohols and Biodiesel) Ap-
plications as Fuels for Internal Combustion Engines,”
Progress in Energy and Combustion Science, Vol. 33, No.
3, 2007, pp. 233-271. doi:10.1016/j.pecs.2006.08.003
[6] J. C. Pasqualino, D. Montané and J. Salvadó, “Synergy
Effects of Biodiesel in the Biodegradability of Fossil-
Derived Fuels,” Biomass and Bioenergy, Vol. 30, No. 10,
2006, pp. 874-879.
doi:10.1016/j.biombioe.2006.03.002
[7] G. Francis, R. Edinger and K. Becker, “A Concept for
Simultaneous Wasteland Reclamation, Fuel Production,
and Socio-Economic Development in Degraded Areas in
India: Need, Potential and Perspectives of Jatropha Plan-
tations,” Natural Resources Forum, Vol. 29, No. 1, 2005,
pp. 12-24. doi:10.1111/j.1477-8947.2005.00109.x
5. Acknowledgements
The author is grateful for the data obtained from SADC
Head office in Gaborone, Botswana.
[8] US Energy Information Administration, “World Carbon
Dioxide Emissions from the Consumption of Petroleum,
1980-2005. International Energy Annual 2005”.
http://www.eia.doe.gov/emeu/international/energy.html
REFERENCES
[1] B. Amigun, R. Sigamoney and H. von Blottnitz, “Com-
mercialization of Biofuel Industry in Africa: A Review,”
Renewable and Sustainable Energy Reviews, Vol. 12, No.
3, 2006, pp. 690-711. doi:10.1016/j.rser.2006.10.019 [9] T. M. Lillesand and R. W. Keifer, “Remote Sensing and
Image Interpretation,” John Wiley & Sons, New York,
Chichester, Brisbane, Toronto, Singapore, 1987.
[2] Renewable Energy Policy Network for 21 Century Report,
“The Potential Role of Renewable Energy in Meeting the
Millennium Development Goals”.
http://www.ren21.net
[10] P. L. G. Vlek, Q. B. Le and L. Tamene, “Land Decline in
Land-Rich Africa,” Science Council, Consultative Group
on International Agricultural Research, London, Montpel-
K. B. MFUNDISI
42
lier, 2008.
[11] Southern African Development Community, “Food Secu-
rity Early Warning System. Agromet-Update 5,” 2007.
[12] B. V. S. Reddy, A. A. Kumar and S. Ramesh, “Sweet
Sorghum: A Water Saving Bio-Energy Crop,” Interna-
tional Conference on Linkages between Energy and Wa-
ter Management for Agriculture in Developing Countries,
International Water Management Institute, The Interna-
tional Crops Research Institute for the Semi-Arid Tropics
Campus, Hyderabad, 29-30 January 2007, pp. 1-12.
[13] C. De Fraiture, M. Giordano and Y. Liao, “Biofuels and
Implications for Agricultural Water Use: Blue Impacts of
Green Energy,” Water Policy, Vol. 10, No. 1, 2008, pp.
67-81. doi:10.2166/wp.2008.054
[14] Government of Botswana, “Botswana National Atlas,”
Department of Surveys and Mapping, Gaborone, 2001.
[15] Government of Botswana, “Report on the Feasibility
Study for the Production and Use of Biofuels in Bot-
swana,” Department of Energy, Gaborone, 2007.
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