Both countries heavily rely on cereals as the main source of calories. In terms of weight, maize and rice were the most important cereals entering the cities, followed by millet, sorghum and wheat (Triticum aestivum
L.; Figure 5
and Figure 6
). In Burkina Faso, millet, maize, and sorghum are the most important food commodities for household consumption [44
]. While millet is the major staple for the most vulnerable households, sorghum and maize are consumed by the majority of households (ibid.). The relatively small incoming quantities of millet and sorghum as compared with maize and rice can be attributed to the fact that these crops are typical subsistence crops. While most of the maize was supplied by national sources, more than 90% of the rice was imported, out of which approximately 70% came from Côte d’Ivoire to Burkina Faso via railway as revealed by secondary data. It is, however, likely that rice imported via railway also supplies other urban centres along the route such as Bobo-Dioulasso. Therefore, the figure probably overestimates the quantity of imports and has to be treated with care. Elbehri (2013) [17
] and FAOSTAT (2013) [45
] reported smaller numbers at the national scale: According to FAOSTAT (2013) [45
], the share of imports in relation to rice supply was about 60% for the year 2013. Elbehri (2013) [17
] stated a decrease of the proportion of rice supply covered by domestic production from 70% in the mid-1990s to less than 30% today. Another likely reason for the gap between our results and figures in the literature stems from the fact that imported rice is being transported mainly to the capital from where it is redistributed to other places in the country. Our data showed that more than 60% of the rice, likely most of it imported, left Ouagadougou again.
The resulting dependence on imports can be attributed to a rising consumption of rice particularly in urban centres and a relatively lower productivity [17
]. According to our data, imported rice passed mainly through the neighbouring country of Côte d’Ivoire that has historically been the major transit route for exports from, and imports to, the landlocked country [32
]. Smaller quantities also passed through Togo and Ghana.
As in Burkina Faso, in Ghana, rice is also associated with an urban diet, with per capita consumption of rice in urban areas accounting for about 76% of total rice consumption (CARD, 2010 cited by [46
]). Ghana is also far from self-sufficient for rice, importing more than 50% of its domestic demand in 2013 [45
], even though rice production has increased in the recent decade. Between 2003 and 2013, it has more than doubled from 238,810 to 569,524 tonnes. Although production takes place in all regions of the country, the Northern Region is a major production area providing almost 40% of the domestic supply [46
]. The geographical proximity of production may be the reason for a higher level of self-sufficiency in Tamale as compared with the national average. According to our data, 14%–20% of the rice was imported in the lean and peak season, respectively. Other cereals—apart from wheat—were also produced in close vicinity to the city. Warehouses in the source communities ensure stable supply across seasons. Cereals, foremost maize, and also other staples such as yam, beans (Phaseolus vulgaris
L.) and groundnut (Arachis hypogaea
L.) were exported from Tamale to the central and southern parts of the country in both seasons. The importance of these staples for Tamale as compared with Ouagadougou becomes obvious when comparing the incoming quantities per capita (Figure A7
For Ouagadougou, Bobo Dioulasso was a major supplier of maize (in both seasons) and millet (particularly in the lean season). The western part of the country is known as a surplus production area for cereals [47
]. Apart from Bobo Dioulasso, millet also came from Pouytenga in the peak season and from Fada N’Gourma in the lean season. These towns are important wholesale markets, attracting produce from the millet surplus areas in the east (as confirmed by Haggblade et al., 2012 [26
]), and facilitating cross-border trade. For instance, cereal trade flows between Burkina Faso, Ghana and Niger are directed through the large cross-border market in Pouytenga [48
]. Our data confirmed that considerable quantities of maize left Ouagadougou for Niger, while millet was exported to coastal countries.
Cross-border trade in West Africa is considered to be far below its potential extent, considering the diversity of agroecological zones. This is due to high transaction costs caused by limited transport and communication infrastructures, fragmented regional markets and lack of predictable trade policies ([17
]; Box 2
). Even though ECOWAS was established to promote free trade, numerous barriers prevent translating the official commitment into practice [17
Box 2. Transport Costs and Prices in West Africa.
In West Africa, there are manifold factors increasing transport costs and causing delays on the roads including slow and costly trade procedures and informal taxation at the borders [17
]. According to OECD (2013) [49
], transportation costs even exceed tariffs in cost and delays on border crossings; further, coordination problems and harassments significantly contribute to the total transport costs. As a response, the West Africa Trade Hub (WATH) project was funded to provide information on, and to fight, road harassment ([50
]; Figure 7
). The WATH project found that in Burkina Faso and Ghana there are, on average, five control points per 100 km and that the average amount of bribe cost per 100 km was USD38 for Burkina Faso and USD10 for Ghana. The average time spent at the control points per 100 km was 45 min for Burkina Faso and 35 min for Ghana [51
]. That means that for a trip from Accra to Ouagadougou, drivers have to spend, on average, USD146 on informal payments, and have to spend more than 6 hours on more than 50 check points, the border not included.
In addition, cartels that control transport services charge high transport prices despite an aged vehicle fleet and poor services, resulting in far higher prices than in developed countries [52
]. Thus, even if external measures are being taken such as lowering fuel prices to reduce transport costs, it would not have an impact on the price which is determined by the trucking market.
Fish plays an important role in both the Burkinabe and Ghanaian diets and contributes to the necessary protein intake given the heavy reliance on staple crops [53
]. In Burkina Faso, urban households spend 11% of all expenditure for (unprocessed) food on fish, while households in Ghana even spend almost one quarter of their food expenditure on fish (Table A2
). Ghana is one of the few countries in the world where fish accounts for more than 50% of the population’s animal protein intake as compared with the world average of 17% [53
]. Therefore, it is not surprising that fish dominated the incoming animal sources in both cities (Figure 8
and Figure 9
). However, outgoing flows need to be considered, whereby in Ouagadougou up to 28% of the fish left the city again for other places in the country. In Ouagadougou, the greater part of the fish was imported from Senegal and Mali (dry fish) as well as from Ghana (fresh fish). However, since Ghana cannot meet its own fish demand by the domestic catch, it is likely that fish coming from Ghana had its origin elsewhere. National data show that currently, in Ghana, two-thirds of domestic consumption is covered by domestic supply, while one-third is met by imports [54
]. One-quarter of the total domestic fish catch in Ghana is met by inland fishery (ibid.). According to UN Comtrade (2015) [55
], the major exporting countries in 2015 were EU countries (50%) and Togo (39%). Our results revealed that in Tamale, 83%–87% of the supply passed through the port of Tema and a small proportion also originated from central Ghana.
The livestock sector is a major pillar of Burkina Faso’s economy contributing more than 18.6% (including forestry and fisheries) to the country’s GDP and accounting for 25% of its export earnings [30
]. Almost 300 cows entered Ouagadougou daily during the peak season. The main source was Dori in the northeast of the country, followed by Yako and Ouahigouya north of Ouagadougou. In the lean season, only half the cattle head entered the city as compared with the peak season. While Sahelian countries have good conditions producing domestic ruminants, the coastal countries are better suited for short-cycle livestock (poultry and pigs), especially in urban and peri-urban zones [17
]. Accordingly, more than half the cattle head were exported, to Parakou (northern Benin), southern Ghana and Pouytenga, a city that serves as a trade hub between Burkina Faso, Niger and Benin. Ghana’s cattle imports has risen five-fold in five years from 7192 head in 1993 to 35,946 in 1998, with Burkina Faso and to a lesser extent Niger as the two main sources [57
]. Live cattle as well as small ruminants entering Tamale, however, came not from Burkina Faso, but from the surrounding areas. Northern Ghana is also suitable for livestock-keeping and even exported to the central and southern parts of the country; however, the main livestock trade occurred between Burkina Faso and the coastal cities of Ghana, passing through Tamale. Not only cattle but also small ruminants (sheep and goats) were exported from Burkina Faso to southern Ghana. They originated from dispersed sources in the central part of the country. In general, livestock-keeping is a potential source of income rather than for self-consumption and can be considered a risk-reducing strategy [57
]. Therefore, it is difficult to assess the amount of meat that is being consumed in the two cities using livestock flow data. For example, for Ouagadougou, cattle are fattened in the city and it is only weeks later that they are exported to other countries. Consumption data may be a more reliable indicator of meat consumption.
Yet, generally, demand for livestock products including poultry is expanding in West Africa as a result of population growth, increased urbanisation, and rising incomes [58
]. In many West African countries, the growing demand for poultry has been met by cheap poultry imports from Europe which was critically discussed given the “huge, untapped domestic poultry industry” in the region [17
] (p. 32). This was made possible after the introduction of the Common External Tariff (CET) in West Africa that reduced the tariff rate to 20% [59
]. It has had differing effects on poultry markets in the region, with some countries experiencing large import flows of frozen poultry such as Ghana and others like Burkina Faso receiving very little [58
]. Schneider et al. (2010) [59
] noted that despite similar import regulations and tariffs domestic production of chicken accounted for almost 100% of total consumption in Burkina Faso. This is reflected by the large inflow of live chicken into Ouagadougou. Our data showed that 16,000 chicken and 1000 guinea fowls entered the city daily, mostly by motorbike (Figure 10
). Schneider et al. (2010) [59
] assumed that the country’s landlocked location, and the far distance to the next port prevented the influx of frozen poultry from Europe. Hence, trade barriers including high transport costs can, in some cases, also protect domestic production. On the other hand, Ghana imports more than half of its poultry supply [59
] despite a flourishing poultry industry in the late 1980s [60
]. This is reflected in the small number of chicken entering the city per day: 120–770 chicken and 300–245 guinea fowls in the peak and lean season, respectively.
Apart from onion (Allium cepa
L.), urban vegetable supply in Ouagadougou was met by domestic production, albeit with large seasonal differences (Figure 11
). In the peak season, vegetables entering the city stemmed from surrounding areas, while in the lean season, vegetables were produced in various locations throughout the country. It is likely that peri-urban areas of Ouagadougou and the rural hinterland take advantage of the proximity to the urban market in the peak season when weather conditions allow the cultivation of vegetables almost everywhere. In the lean season, however, vegetable production is limited to locations where irrigation water is available. Tomato (Lycopersicon esculentum
L.) was produced in irrigation schemes such as in Yako, Titao, Kongoussi, while eggplant (Solanum melongena
L.) as well as zucchini (Cucurbita pepo
L.) came from irrigation schemes close-by, such as from Loumbila, Ziniare, and Zitenga. Most of the cabbage (Brassica oleracea
L.) was provided by areas close to Bobo Dioulasso. Part of the onion supply was produced in the country, and sourced from mainly Fada N’Gourma and Koupéla; but especially in the lean season the amount of imported onion from Niger exceeded domestic supply. Secondary import data at national scale indicate that apart from the largest exporter, Niger, onion is further imported from the Netherlands and Morocco to Burkina Faso. On the other hand, onion production in Burkina Faso is increasing and exports exceed the amount of imported onion [45
]. Our data revealed that in both seasons, onions left the city again to Côte d’Ivoire and Ghana. Our data also showed that large volumes of onion moved from Niger and Burkina Faso to central and southern Ghana, passing through Ouagadougou and Tamale. Hence, no onions from Burkina Faso were recorded to end in Tamale and only a small part of the onion supply entering Tamale came from Niger. Informal interviews indicated that even though onions from Niger are appreciated by the customers, trade relationships are not yet well established between traders in Tamale and Niger. For example, traders on the Tamale market would be granted credit by their long-known supplier from Bawku in North Ghana while they had to pay for onions from Niger in cash (personal communication).
Apart from onion, tomato was traded across borders. According to secondary customs data, tomato produced in Burkina Faso in irrigated agriculture during the lean season was exported mainly to Ghana and Benin. Turnover in Ouagadougou before continuing to Ghana may explain the higher quantities of incoming tomato to Ouagadougou during this season. This is reflected in our data: Tamale sourced 84% of its tomato from Burkina Faso in the lean season (Figure 12
). In the peak season, central Ghana, in particular Techiman and surrounding communities, provided fresh tomato from rain-fed cultivation. Market data collected on a monthly basis revealed that in January and February, Northern Ghana with its towns Navrongo and Bawku are additional suppliers in the lean season. However, the tomato industry in Northern Ghana has experienced a decline in the past years [61
]. Tomato from Burkina Faso is considered of superior storage quality and therefore has higher retail prices [64
] which was confirmed by informal interviews. Moreover, tomato paste imports surged in the 2000s, from 24,654 tonnes in 2003 to 109,513 tonnes in 2013, providing a low-cost substitute to fresh tomato. Other vegetables supplying Tamale such as hot pepper (Capsicum
spp. L.) and okra (Abelmoschus esculentus
L.) were produced in close vicinity to the city and the only crop that was only available seasonally was avocado (Persea americana
L.) coming from the central part of Ghana as well as cabbage albeit with hardly any seasonal variaton.
For Tamale, urban agricultural production could be captured by data collected at the inner urban market. These data revealed that urban agriculture supplied traditional leafy vegetables such as jute mallow (Corchorus
spp. L.), roselle (Hibiscus sabdariffa
L.) and amaranth (Amaranthus
L.) as well as exotic leaf vegetables such as lettuce (Lactuca sativa
L.; Figure 13
). Leaves take a substantial part of traditional diets and are an important source of Vitamin A. These were not the only crops cultivated in urban areas but the only ones that were supplied exclusively by urban farming. The perishable nature of the produce does not allow for long transport routes due to the lack of cool storage. Hence, crops produced in urban areas benefit from close proximity to the urban market. This has been documented for many African and Southeast Asian cities [65
] in general and for Tamale and Ouagadougou in particular [33
]. According to Drechsel and Keraita (2014) [66
], 80% of the cabbage supply was provided by urban agriculture in Tamale. This could not be confirmed by our data according to which only 3.6% and 6.2% of cabbage was sourced from within the urban area in the lean and peak season, respectively. It has to be noted that incoming quantities are rather conservative estimates, since only those volumes entering the main marketplace in Tamale were captured, while street sellers have not been considered who may market a considerable proportion of the leafy vegetables. Moreover, backyard gardening for subsistence as well as for commercial purposes is common [33