Challenges to ecosystem services of sustainable agriculture in West Africa

Food security is still sub-optimal in many parts of West Africa calling for more efficient agricultural practices in mitigating food insecurity. Some of the problems faced in West African agricultural systems are bottlenecks in ruminant livestock supply, inefficiency in commercial poultry production, and loss of arthropod diversity. These issues require proper integration of farming systems, demand the closing of nutrient cycles, need diversi cation of production, and require enhancement of ecosystem services. To contribute applicable data for the attainment of the aforementioned, this study investigated four topics of different contexts such as livestock and forage trade, nutrient use efficiency and detoxification of alternative feed through biochar application in poultry production, and lastly ecosystem service provision by studying arthropod diversity in cash crop elds of urban and periurban agricultural systems (UPA). The knowledge of production and consumption regarding livestock and forage trade in West Africa is largely unknown and data are often rough estimates only. To shed light on the routes and hubs of livestock, a study was conducted in Bamako, Mali, where all major roads connecting the city were monitored for 24 hours each day for seven days, across the hot, rainy and harvest seasons. Information was collected on three ruminant livestock, goat, sheep, and cattle transported by vehicles. The origin, destination and quantity of the transported livestock were recorded. Data was also collected on the frequency of animal feed tra cked across these roads. Results showed that sheep were the most tra cked livestock of the three, due to its importance in Islamic festivals. The traffic of cattle and sheep was extensive, whereas the transport of goats was smaller and more localized. The results also showed the importance of Bamako as a hub in the livestock distribution to countries like Guinea and Senegal. Information obtained contributes signi cantly to the understanding of the scope of policy interventions towards further enhancing the efficiency of the livestock production and distribution sector and the enhancing of food security. Another important component of food security is linked with nutrient use efficiency in livestock production systems, including the poultry sector. To specically address this, two experiments about the efficacy of biochar in poultry management were conducted in Tamale, Northern Region, Ghana. In the first experiment, 24 male broiler chickens were offered commercial broiler finisher diets with 0 %, 1.5 %, 3 % and 6 % wood charcoal. The birds underwent a 14-day adaptation period and a four-day data collection period. Results showed that amendment of 6 % wood charcoal to feed stuff does not negatively a ect growth performance. Although the amendment of biochar did not signi cantly reduce weight gain, the 6 % biochar application slightly reduced the mean weight of those chickens. Hence more research is needed in this regard to investigate the underlying conditions that may make biochar a better poultry feed additive. Despite this, the biochar diets reduced the amount of phosphorous excreted by the chicken. It follows that at least phosphorous as a nutrient was more available to the birds. The issue of nutrient use inefficiency in West Africa poultry management is an important one as commercial feed is the most important variable of poultry production cost. Hence, this potential of biochar to accrete nutrients could benedicial for farmers if explored more. In the second biochar experiment, 168 female broiler chickens were offered seven diets that included different levels of biochar with different processed states of the underutilized carbohydrate rich root tuber, Icacina oliviformis. The root tuber is ubiquitous in the Northern Region of Ghana and has been consumed by indigenes in the past during famine periods. Despite its rich carbohydrate content, the wild crop contains antinutritive factors like terpenes, which inhibit essential amino acid receptors in poultry. Despite this, some other Icacina spp. also possess detoxing properties against tetrachloromethane and antimicrobial properties against Escherichia coli, Staphylococcus aureus, Streptococcus spp, Candida albicans, and Klebsiella pneumoniae. Results from the experiment showed that soaking the root tuber in water and feeding to poultry did not have any e ect on lipophilic compounds but reduced chloroform subfractions. The addition of biochar on reducing the antinutritive effects was slight; furthermore, it resulted in low chicken body weight and blood protein. To this end, it is evident that despite the carbohydrate rich source of the root tuber, further research and breeding is needed on improving this wild plan species to make it a potential substitute for maize in poultry feeding to contribute to food security in West Africa. As food and forage production is largely dependent on ecosystem services of arthropods (such as pollination, biological pest control, nutrient decomposition), the final study looked at the arthropod assemblage in UPA systems of Tamale. Species were sampled across lettuce, okra, and pepper fields within different management intensities. Two sampling techniques, pan trapping and pitfall trapping were used to sample the arthropods. Parameters such as wastewater irrigation, pesticide, and weedicide application, as well as manure and synthetic fertilizer usage, were assessed. From the results of 14,226 sampled arthropods, comprising 81 families, 11 orders, 211 genera, and 244 species were identified. Multivariate analyses showed that irrigation regimes had significant effect on arthropod species abundance, with Hippeleates pusio the most dominant, consistent with locations using wastewater as irrigation. This vector not only transmits diseases like mastitis to livestock as well as bacterial conjunctivitis and yaws to humans. All these diseases are still prevalent in the study region. In addition, three alien ant species were recorded in the samples. The issue with ant species is that some of them form mutualistic association with deleterious aphids, which have the potential to cause serious crop damage. The other issue of concern with the ant species sampled is that they have the potential to grow into large populations, by displacing other native ant species and become invasive. Both issues may cause serious implication on food security for Tamale and beyond. Thus, future arthropod ecological research should not only evaluate the influence of wastewater application on H. pusio populations and related disease incidence but also the effect of alien and other arthropod species present in the area and their relationship with human food security.