Africa & Irrigation

 In my previous blog, I mentioned and explored ways in which water scarcity can be tackled. This week’s blog is tightly linked to that as agriculture is the most water-intensive industry and the biggest industry in Africa, home to 60% of the world's arable land. I found the above quote from Obama very interesting as there is obviously not one solution to this, but without a doubt, colonial legacies and lack of investments have partly influenced Africa’s ability to achieve self-sufficiency. Irrigation strategies have been deemed by many scholars to be the solution for Africa to escape inefficient crop plantations and hunger. Irrigation is the controlled application of water for agricultural purposes through manmade systems to supply water and meet the requirements not satisfied by rainfall. However, irrigation methods are not all the same, so I believe it is important to highlight and provide an overview of the different irrigation practices that exist. 

 Overview of irrigation practices 

 All irrigation practices share the same purpose, which is to increase crop yields and prevent hunger using a dependable water source, especially when irregular weather patterns appear, e.g. droughts (Shiferaw et al, 2014). Irrigation draws water from existing sources such as groundwater, rivers, wells which gets fed into pipes end up spraying the water crops. Although irrigation-fed crops have a more dependable water supply, there is a risk of contamination if the water source becomes impure. This occurs when heavy rainfall causes agricultural runoff of fertilisers or insecticides into freshwater lakes, a process called eutrophication, which can severely impact water quality. Ultimately, food-borne illnesses arise and spread having detrimental effects on human health . Furthermore, irrigation practices are severely water-intensive and if overused, water sources will diminish or even disappear. An alternative to irrigation is rain-fed farming which depends on direct rainfall and is safe from contamination but much more sensitive to droughts, especially as climate change is intensifying unpredictable weather patterns.

 The Centres For Disease Control and Prevention website display a list of different irrigation systems:

 - Localized irrigation

 - Sprinkler irrigation

 - Sub-irrigation 

 - Manual irrigation

 - Centre pivot irrigation

 - Drip irrigation 

 - Surface irrigation 

 - Lateral move irrigation 

Figure 1: Centre Pivot Irrigation

As we established at the beginning of this entry, agriculture is the largest industry in the continent, where there is vast amount of arable land. However, only 6% of farmland is actually irrigated. When I stumbled across this statistic I found it very surprising and almost hard to believe that a continent so heavily reliant on agriculture has the lowest irrigated acreage and water storage capacity in the world (Shiferaw et al. 2014). In order to prevent continuous hunger during drought seasons, it is imperative to increase this percentage of irrigated land as it ensures stable crop yields all year round. The underdevelopment of irrigation systems in Africa is largely due to high costs and accessibility as many small-scale farmers do not have the funds or adequate education to operate such new technologies (Perry, 1997).

Despite this, it is important to note that efforts to improve and apply irrigation systems in Africa are beginning to pick up speed in recent years. According to Woodhouse et al (2016), a reliable water source must be established for farmers before they implement such systems, especially in sub-Saharan Africa. In order for this to occur, it is essential to reassess the way irrigation is developed with a specific consideration and focus for small-scale farmers. The consideration of small-scale farmers’ needs and interests is fundamental as by doing this local African farmers can adapt to new technologies and it reassures them that these systems will benefit them (Woodhouse et al. 2016).

Downside?

 Although irrigation is vital for watering crops during low rainfall seasons, it is important to mention that irrigation systems can have negative involuntary effects. According to Alter et al. (2015), a large-scale irrigation scheme called the Gezira Scheme applied in East Africa has massively shaped local rainfall patterns. This can have detrimental impacts on neighbouring communities, especially if they rely on rain-fed farming. The study highlighted that rainfall increased to the east, but was hindered over the Gezira Scheme area. A climate model was used to confirm this change and it soon became apparent that the regional rainfall patterns were changing. Although some communities may have increased crop yields and water storage due to extra rainfall, those who receive a reduced amount of rainfall suffer, especially if there is a reliance on rain-fed farming. Therefore, during the decision-making process, it is imperative to consider surrounding communities before large irrigation systems are installed.

Figure 2: Illustrates the types of biomes in the Gezira Scheme and the areas with irrigation (Alter et al. 2015)