A Watery Stroll Down the Hill - Ethiopia's Oromia Region and the Determination of Agriculture

During my ambling through reading this week, I happened upon something I found rather interesting. It caught my attention, intrigued me, and became the focus of a whole morning. The thing in question was a transect, from Tucker et al.’s (2014) investigation into domestic water use in the Oromia Region of Eastern Ethiopia, which runs from highland (above 2,300m), all the way down to the lowland flats (below 1500m).

Tucker et al. 2014

This week’s blog was initially intended to focus around groundwater distribution in Africa, however you’ll all have to wait a little bit longer for that absolute corker. Instead, I’d like to dissect the above transect, which, as you may have realised, is a perfect living example of how water availability (and topography) can define the agricultural landscape.

Tucker et al. (2014), in their unquestionable wisdom, split the transect into three “Livelihood Areas” – the classic Wheat, Barley and Potato zone (at the peak of around 2300m), the unforgettable Sorghum, Maize and Chat zone (1500 – 2300m) and of course everyone’s favourite the Shinile Agro-Pastoral zone (1500m). For the sake of ease, I think we’ll start at the top, and work our way down.

Tucker and friends, in their analysis of the Wheat, Barley and Potato zone (which for the sake of sanity we will henceforth refer to as the WBP zone), paint a very revealing picture of how water availability affects agriculture. The topography is described as rugged, with isolated hills and depressions, with no major rivers. This, combined with low storage aquifers and shallow groundwater tables, starts to paint a picture of water scarcity. The main source of water here is instead from highly seasonal rains of usually about 700 – 1000m which occur from March to April (short rains) and from June to September (main rains). 

 

Due to the lack of groundwater, agriculture here is consequently rain-fed, however this is difficult due to the temporality of water supply. For this reason, potatoes are favoured (partially due to their relatively shorter growing season), as is wheat, owing to its generally hardy nature allowing it to survive in the highland soils, and even stand up to a bit of a water deficit (FAO).  Livestock agriculture is low, largely due to the large amounts of water required year round by our animal friends. The majority of this food is for subsistence; only a few of the richer landowners grow any forms of cash crop.

Don't be too jealous that people in the WBP zone like 'taters best

This agriculture is undeniably a product of its environment; conditions are harsh and water is seasonal and generally unavailable in the dry season, so locals make do with subsistence crops and limited agriculture.

Further down the hill, in the good old Sorghum, Maize and Chat (SMC) Livelihood zone, things are wildly different. Although rainfall can be less (550mm – 900mm), groundwater is far more available, due to the presence of medium-storage faulted volcanic and sedimentary aquifers (big shout out to karstic limestone for making this possible). Not only is groundwater there, but it’s also more than accessible to the locals, due to the shallow water table. 

The variety of water sources means that water is generally more consistent in the SMC than in the WBP zones – it comes from rainfall harvesting, cold springs, ponds, seasonal streams and hand dug wells. Here, there is more of a sense of security regarding water, and all the eggs aren’t in one basket. This means that here, the agriculture is a bit more adventurous. Cash crops abound – from chat to cereals, and even some livestock rearing. Sorghum and Maize both make an appearance, being highly efficient users of water in their own right, and definitely able to stand up to a bit of shortage (FAO).

Of course, the relative focus on cash crops in the SMC isn’t purely due to water availably; roads and markets are far more accessible – however it does play a large role in enabling such crops to be grown in the first place.

Last but not least, we come to the Shinile Agro-Pastoral (SAP) zone. Here, rainfall is lowest of all, clocking in at 400mm – 700mm a year. The SAP’s secret, however, is that it sits on what is essentially a motherlode of groundwater; high storage volcanic aquifers abound in this flat lowland. The SAP’s downfall, however, is that apart from riverbed harvesting, it is hard to get at this deep groundwater. Most agricultural projects therefore take the shape of big commercial units, who can afford borehole access to this sunken treasure.

If anything there is too much groundwater

 

But what commercial agriculture you do find is relatively booming. Many profitable industries exist, with a distinct focus on livestock production due to the large amounts of water available here – these are only bolstered by the ease of access in and out of the region. Here, agriculture has taken the plunge and become almost fully commercial.

 

So, as we have travelled down the hill, we have seen much change in agricultural practice. A few patterns in particular strike me as interesting. The first is that as you move downhill and to areas with more water to throw about (and of greater temporal consistency), you see a clear trend from mere subsistence to “cashing in” on cash crops and livestock. People seem to take more risks when the safety net of water is more prominent. Secondly, agriculture seems to become more developed as water resources become greater and more promising. In the WBP and SMC zones there are few developed groundwater tapping schemes, however these abound in the SAP zone where the promise of water comes with promise of profits. One thing here seems obvious - Jack and Jill are heading in the wrong direction to fetch their pail of water.

It appears then that agriculture in Africa is a bit of a two-sided coin; on the one hand, you have the areas in which water is generally guaranteed and money can be made - and on the other, those on the periphery who do their best just to get by. There is little question about which recieves the majority of investment.

Trends like these, I believe, will be found to be common in the upcoming weeks.