Assessing the Availability of Land and Water Resources for Production of Energy Crops in Southern Africa

doi:10.4236/jsbs.2012.23006

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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: [email protected], [email protected]

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-

K. B. MFUNDISI

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

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

K. B. MFUNDISI

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.

K. B. MFUNDISI

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

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