Irrigation is ‘the artificial application of water to land
to assist in the production of crops’ (dictionary.com). It involves the storage
and transportation of water to fields for agricultural use. Large-scale
irrigation has transformed the world of farming in the West, but there are many
obstacles in Africa that have prevented large-scale irrigation practices from
becoming a mainstream method. Africa’s agricultural productivity is currently
the lowest in the world and the lack of irrigational practices may be to blame
(You et al. 2010). Some would argue that this is an example of Africa ‘lagging
behind’, but is making large-scale irrigational practices mainstream really the
best answer for Africa’s farming future? The IFPRI Discussion Paper (You et al. 2010) states that irrigation in Africa has the potential to increase agricultural
productivity by at least 50% more than what it is currently.
According to the Food and Agriculture Organisation (FAO),
the total area of irrigated land in Africa almost doubled to 13.6 million ha in
2008, compared with 1961. However, in 2008, only 6% of arable land in Africa
was irrigated, compared to 47% in Asia (FAO 2010). As I only wish to discuss
the history of irrigation briefly, I will stick to the irrigation history of
the Sub-Saharan region, where irrigation has been heavily dependent on aid,
similar to other regions of Africa. When the Sub-Saharan countries gained independence
throughout the 1950s and 1960s, large-scale irrigation schemes were set up in
order to boost development, which were primarily supported and funded by aid
agencies. Between the 1970s and 80s, productivity of large-scale irrigation
schemes increased, but large foreign debts of the Sub-Saharan countries meant
that government budgets including agriculture budgets were cut, and
subsequently, the maintenance of irrigation schemes soon declined. With poor
results from aid investments, the focus moved to participatory small-scale
irrigation developments, which have now become
more mainstream (Sakaki and Koga 2011). However, 95% of Africa’s crops are
still rainfed (You et al. 2010). Of the remaining 5%, many are irrigated using
traditional methods, rather than large-scale schemes, which has further
prevented the optimum productivity from being reached. Due to relatively small
scale farming practices in rural areas, large irrigation practices have become
hard to implement due to financial costs and scales. So whilst the literature
surrounding farming in Africa frequently highlights the missed opportunities
for increased yields due to the lack of irrigation, is irrigation really the
best way to move forward?
The most important advantage of irrigation is that it allows
for the continuous cultivation of crops all year round. Rainfall in Africa is
highly seasonal and varies spatially, primarily due to the movement of the
Inter Tropical Convergence Zone (ITCZ) (Taylor 2004). In addition, a high
amount of rainfall is lost due to high evapotranspiration rates. This limits
what can be grown throughout the year, but with irrigation, water can be stored
and used as needed. Furthermore, with climate change, the occurrences and
intensities of droughts are expected to increase (Wanders and Wada 2015), thus,
the use of irrigation would contribute to an increase in food security as
droughts would not severely affect yields if water can be guaranteed at any
time.
All this sounds good, but in practice, irrigation,
especially large-scale schemes can have a huge impact spatially, not just in the
area it is being used in. This is especially worrying as water is already a
scarce resource in the region. Let’s go back to the basics – water for
irrigation can be taken from the local precipitation, natural water systems
such as rivers, lakes, and wetlands, and renewable and non-renewable
groundwater (Wada et al 2012). We should be concerned with 2 of these; non-renewable
sources and transboundary rivers, especially those with irrigation schemes
upstream affecting countries downstream. Without adequate management, it is
easy to get carried away with over exploitation of water due to the visible rapid
increases in productivity. So food security with groundwater-fed irrigation may
increase food security in the short-term, but it is not a solution for the long
term. Not only do we need to consider what the sources of irrigation are, but
also the impact on the local ecology. A study in South Africa showed how
fish communities were being negatively affected by a large-scale irrigation
scheme that supported a variety of cash crops (Malherbe et al 2015). Fish
remain a vital protein source for Sub-Saharan Africans, and if fish populations
are negatively affected by large schemes, then a critical food source could be
lost, compromising food security, as well as many livelihoods (The Guardian 2013). Most importantly, we also need to consider Africa’s growing population
size and density. So whilst irrigation may make the region increasingly
food secure, it will deplete the amount of water available for other basic
needs such as sanitation and drinking in nearby settlements, affecting the quality
of life.
Whilst there is certainly potential for large-scale
irrigation to transform Africa’s farming future, the shortfalls of irrigation
discussed show that Africa should not become totally dependent on large-scale irrigation.
In my opinion, sustainable, small-scale irrigation schemes should be developed
further. Not only would this be better for the environment, but also more
equitable socially and economically. Although I did not talk about cost in this
specific post, affordability of irrigation schemes remain an obstacle to many
farmers, most of whom are living in poverty. So irrigation as a means of
development could be a disaster if water sources are not equitably divided
amongst other necessary uses, but it could be much more of a positive addition
to the farming methods of Africa if used in a sustainable and small-scale manner.
