'Water is both an indispensable input and a key constraint'. As illustrated in previous entries, the current water condition in Africa, as it pertains to food production, needs more efficacy in water management, and increasingly so, due to climate change effects on hydrology. Expansion of irrigation, particularly groundwater, could be an effective adaptive strategy for the growing population. However, inherent hydrological inequalities pose great challenges and droughts threaten rain-fed livelihoods where potential for irrigation is limited. There exist methods of enhancing rain- fed productivity but they employ temporally and water quality sensitive approaches which are difficult to maintain.
What’s the matter (and why does it matter)?
Drylands of tropical Africa contain 50% of the region’s population, including 75% of the poor. Agriculture is the most important contributor to dryland economies, which, in turn, are notably significant in 20 countries of tropical Africa. For example, drylands make up 46% of cultivated land in Western Africa (Ward et, al. 2016). Commonly the spatial distribution of surface and ground water sources is problematic (far away from settlements), which leads to them being underdeveloped and underused. Renewable water withdrawals in the region are at a rate below 30% of the global average and the level of irrigation development is lowest in the world. This presents an opportunity for suitable and sustainable water management moving forward, which would include both small-scale, low tech and large-scale, high-tech schemes. The potential for small-scale irrigation in the tropical Africa drylands is up to 11.6 million hectares, and for large-scale up to 2.5 million hectares. Whether small or large scale, the financial investment needed is substantial - in the dryland region alone, an estimated 4,500 and 12,000 USD, respectively. According to IFPRI model, 7-8% of cropland could be developed for irrigation with ‘acceptable rates’ of economic return which would have a ‘transformational impact’ on drylands agriculture and livelihoods. Drylands more generally are also battling the public perception of the degree of their importance. A Rio 1994 Convention to Combat Desertification, focused on halting soil erosion and restoring fertility, has been significantly underfunded as it is perceived as not important enough globally, compared to climate change and biodiversity conventions (Gassner, et al., 2021).
To the moon and back…to traditional knowledge
In terms of food production (the focus of this blog) across tropical Africa, rain-fed cultivation meets 90% of the demand for staple foods. Moreover, growing staple crops using irrigation in this region, more often than not, fails to be economically viable. Therefore, the drylands should strategize rainwater management to achieve food security and promote irrigated cultivation of cash crops. In the Sahel, the most sub-Saharan part of Africa, traditional and effective half-moon swales have been used to maximise rainwater entering a field. Pictured in the image on top of the page, half-moons are dug by hand creating mini dam-swale structures which slow down runoff and facilitate water infiltration to deeper layers of the soil, improving moisture conditions for seedlings to take root. Due to natural and climate change-exacerbated erratic rainfall patterns and drought, millions of hectares of Sahel farmland are lost to desertification every year. The people then cut forests down to reveal fertile farming soil, which eventually, too becomes a desert. This is currently happening at a rate of 4 million hectares of forest/year, continent-wide. Meanwhile, an estimated 700 million hectares of degraded land is suitable for restoration (UN, 2022) which is globally significant given the volume of forest it could conserve. The FAO, as part of its Action Against Desertification (AAD), introduced the Delfino plough in Burkina Faso, Nigeria, Niger and Senegal to physically equip the local people to apply their knowledge of the environment for restoration. “The Delfino plough is extremely efficient: one hundred farmers digging irrigation ditches by hand can cover a hectare a day, but when the Delfino is hooked to a tractor, it can cover 15 to 20 hectares in a day”. Then inoculated seeds of native, resilient, and pioneer plants are sown in the ridges, over half a meter deep, to kick-start succession. Simply put, the plough digs the half-moons in soils too dry for it to be done by hand and hence abandoned, allowing to scale up restoration and protection of forests by default.
Your posts demonstrates a thorough grasp of issues of water and food in Africa and a meaningful engagement with relevant literature but referencing format need to improve. It is a well written collection of post that build on each other but could use more details for the specific context of each case study highlighted. By context, i mean what crops or livestock are being grown/reared and how does this intersect with water need and the broad question of food security?
ReplyDeleteThanks for your comment! you're definitely right about the reference, I have revisited that since and think they look more seamless now. It's interesting you say more detail would be desirable as I found myself cutting it out, thinking it made the reading experience more boring; will definitely look into making some additions and reshuffling (as much as word count allows ;)).
ReplyDeleteWhat I hope to articulate through the posts is that, beside the basic biological relation of water and growing food crops, there are other less obvious factors which support or hinder the process of food production, which might be, or should be, the first point of focus to bring about change. Namely, discussed in this post, approach to management and use of tried and tested local know-how.