African cities are growing rapidly into inefficient, unsustainable, resource-starved ecosystems that negatively affect the local economy and food production. Food as a critical resource needs to be produced and managed more efficiently by local communities in the urban area. Urban smart farming (USF) has emerged as an important mechanism to address these challenges to achieve sustainable, resilient, and inclusive cities. USF has the potential to be the industry 4.0 green revolution in agriculture, which embodies innovative digital technologies. However, it is unclear how local African communities and key stakeholders perceive this novel solution and if they are willing to engage in its uptake. This study examines the relationship between the perceived benefits and challenges of USF and the willingness of local African communities to actively participate in USF projects as a potential mechanism to improve local economy and food production. To assess this relationship, a causal model was developed. In this causal model, the local economy and food production were defined as dependent variables. The conceptualized model and the inherent causality between the constructs were validated through a survey administered among African cities’ residents. The results of structural equation modelling indicate a significant positive impact of perceived benefits of USF as well as the willingness of African communities to engage in this technology on local economy and food production. Only minimal adverse effects of the perceived challenges of USF on the local economy and food production have been found. The study concludes that the benefits and willingness of local communities are the key drivers for implementing urban smart farms in African metropolitans. Therefore, it is recommended to focus on the benefits and the motivation of local communities in African cities where USF shall be further developed, rather than on the barriers. The validated causal model can be used as a framework to facilitate the adoption of USF in Africa and consequently enhance the local economy and food production in African cities.

The maintenance of soil productivity is important for sustained crop yield in low-input systems in the tropics. This study investigated the impact of four different land use types, namely, maize and cassava cropping, woodlot/plantations, and natural forests on soil productivity components, especially soil carbon accretion, at six sites within two agro-ecological zones of southern Ghana. Soil properties were significantly different between sites and ecological zones. The coastal savanna zones, which is a low rainfall zone had relatively lower soil carbon storage than the high rainfall forest-savanna transition zone. Soil productivity conditions in the later zone were much more favorable for cropping than the former. Land use types significantly affected the soil carbon (SOC) storage within the two ecological zones. In the low rainfall zone, soil carbon accretion by maize cropping, cassava cropping, and plantations were 48%, 54%, and 60%, respectively, of the forest carbon stock (47,617 kg/ha). In the transition zone, the soil carbon accretion was over 90% of the forest value (48,216 kg/ha) for all land use types. In effect use of land use types in maintaining soil productivity must consider the conditions in a given ecological zone.

The assessment of degradation status of soils in selected areas of Ogbomoso, Oyo state wascarried out. The soil physical and chemical properties were evaluated using mini pits and surface sampling. The laboratory results obtained were compared with the standard indicators and criteria for land degradation assessment according to FAO, 1979. The results revealed that most of the cultivated parts of the study sites were very highly degraded compared to the soil under vegetative fallow which were moderately degraded. The textural class of the soil ranged from loamy sand to sandy loam. Saturated hydraulic conductivity ranged from 1.54 to 3.4 cm hr^-1 corresponding low to moderate permeability. Bulk density ranged from 1.53 to 1.60 g cm^{- 3}. Organic matter was very low in all the study sites. Available phosphorus was low in all the locations. Total nitrogen was predominantly low in most of the cultivated and fallow soils. Exchangeable Sodium Percentage (ESP) of the sites depicted that most of the soils were slightly sodic. Summarily, the soil physical and chemical properties status when compared with the FAO standard show that the area either cultivated or fallow is under degradation. In order to optimize crop production in these areas, there may be need to introduce soil conservation strategies. The practice may include use of crop residues, green manure or poultry manure to boost soil fertility. Also regular monitoring of the fertility status of the soils is required.