Community disaster exposure and first onset of depression: A panel analysis of nationally representative South African data, 2008-2017.

Sub-Saharan Africa faces unprecedented disasters, with climate change expected to exacerbate the frequency and severity of unpredictable and stressful catastrophic events. Unlike developed nations, reconstruction in developing nations is hindered by resource constraints, with certain communities potentially experiencing multiple and enduring effects of disasters. Despite the potential danger of such cumulative community disaster exposure on mental health (e.g. depression), large-scale population-level evidence for the region is limited. We investigated the association between exposure to cumulative disaster and the first onset of depression in a nationally representative survey in South Africa. We used panel data from the South African National Income Dynamics Study (SA-NIDS) from 2008-2017, consisting of 17,255 adult study participants who were depression free at baseline. Risk of first depression onset between individuals exposed and unexposed to community disaster was measured, accounting for multiple disaster exposure over time by fitting generalized estimating equation (GEE) regression models. Data on the geographic location of disasters were obtained from the South African government gazette, and mapped with the government delineated SA-NIDS households' locations. Of the sampled individuals, 2,986 were exposed to disaster during the study duration (17.3%). Increased cumulative community disaster was significantly associated with the likelihood of depression onset (adjusted relative risk [aRR] = 1.20, p<0.01, 95% CI: 1.09-1.33), even after controlling for socio-demographic factors. In sub-group analyses, greater likelihood of depression onset was found among females [but not in men] (aRR = 1.23, p<0.01, 95% CI: 1.09-1.38), Black African [but not in other population group] (aRR = 1.21, p<0.01, 95% CI: 1.09-1.36), lower education attainment group [but not in tertiary and above educational attainment group] (aRR = 1.20, p<0.01, 95% CI: 1.08-1.33), and lower income attainment group [but not in the top income quartile group] (aRR = 1.24, p<0.01, 95% CI: 1.11-1.38), due to cumulative community disaster. Although cumulative community disaster exposure was significantly associated with the first onset of depression, its negative impact may be more pronounced among individuals considered chronically socially vulnerable (i.e. the groups above) in South Africa. Given that many individuals in South Africa rely on social, food parcel relief, and health services from government/public sector, timely access to community-based supportive intervention is needed for disaster survivors, prioritizing socially vulnerable groups to help mitigate problems associated with mental health challenges.

Correction: Multi-criteria suitability analysis for neglected and underutilised crop species in South Africa.

[This corrects the article DOI: 10.1371/journal.pone.0244734.].

Assessing Suitability of Sorghum to Alleviate Sub-Saharan Nutritional Deficiencies through the Nutritional Water Productivity Index in Semi-Arid Regions.

Lack of cereal nutritional water productivity (NWP) information disadvantages linkages of nutrition to water-food nexus as staple food crops in Sub-Saharan Africa (SSA). This study determined the suitability of sorghum (Sorghum bicolor L. Moench) genotypes to alleviate protein, Zn and Fe deficiency under water-scarce dryland conditions through evaluation of NWP. Sorghum genotypes (Macia, Ujiba, PAN8816, IsiZulu) NWP was quantified from three planting seasons for various sorghum seed nutrients under dryland semi-arid conditions. Seasons by genotypes interaction highly and significantly affected NWPStarch, Ca, Cu, Fe, and significantly affected NWPMg, K, Na, P, Zn. Genotypic variations highly and significantly affected sorghum NWPProtein, Mn. Macia exhibited statistically superior NWPprotein (13.2-14.6 kg·m-3) and NWPZn (2.0-2.6 g·m-3) compared to other tested genotypes, while Macia NWPFe (2.6-2.7 g·m-3) was considerably inferior to that of Ujiba and IsiZulu landraces under increased water scarcity. Excellent overall NWPprotein, Fe and Zn under water scarcity make Macia a well-rounded genotype suitable to alleviating food and nutritional insecurity challenges in semi-arid SSA; however, landraces are viable alternatives with limited NWPprotein and Zn penalty under water-limited conditions. These results underline genotype selection as a vital tool in improving "nutrition per drop" in semi-arid regions.

Multi-criteria suitability analysis for neglected and underutilised crop species in South Africa.

Several neglected and underutilised species (NUS) provide solutions to climate change and creating a Zero Hunger world, the Sustainable Development Goal 2. Several NUS are drought and heat stress-tolerant, making them ideal for improving marginalised cropping systems in drought-prone areas. However, owing to their status as NUS, current crop suitability maps do not include them as part of the crop choices. This study aimed to develop land suitability maps for selected NUS [sorghum, (Sorghum bicolor), cowpea (Vigna unguiculata), amaranth and taro (Colocasia esculenta)] using Analytic Hierarchy Process (AHP) in ArcGIS. Multidisciplinary factors from climatic, soil and landscape, socio-economic and technical indicators overlaid using Weighted Overlay Analysis. Validation was done through field visits, and area under the curve (AUC) was used to measure AHP model performance. The results indicated that sorghum was highly suitable (S1) = 2%, moderately suitable (S2) = 61%, marginally suitable (S3) = 33%, and unsuitable (N1) = 4%, cowpea S1 = 3%, S2 = 56%, S3 = 39%, N1 = 2%, amaranth S1 = 8%, S2 = 81%, S3 = 11%, and taro S1 = 0.4%, S2 = 28%, S3 = 64%, N1 = 7%, of calculated arable land of SA (12 655 859 ha). Overall, the validation showed that the mapping exercises exhibited a high degree of accuracies (i.e. sorghum AUC = 0.87, cowpea AUC = 0.88, amaranth AUC = 0.95 and taro AUC = 0.82). Rainfall was the most critical variable and criteria with the highest impact on land suitability of the NUS. Results of this study suggest that South Africa has a huge potential for NUS production. The maps developed can contribute to evidence-based and site-specific recommendations for NUS and their mainstreaming. Also, the maps can be used to design appropriate production guidelines and to support existing policy frameworks which advocate for sustainable intensification of marginalised cropping systems through increased crop diversity and the use of stress-tolerant food crops.

Urban nexus and transformative pathways towards resilient cities: A case of the Gauteng City-Region, South Africa.

Challenges emanating from rapid urbanisation require innovative strategies to transform cities into global climate action and adaptation centres. We provide an analysis of the impacts of rapid urbanisation in the Gauteng City-Region, South Africa, highlighting major challenges related to (i) land use management, (ii) service delivery (water, energy, food, and waste and sanitation), and (iii) social cohesion. Geospatial techniques were used to assess spatio-temporal changes in the urban landscapes, including variations in land surface temperatures. Massive impervious surfaces, rising temperatures, flooding and heatwaves are exacerbating the challenges associated with rapid urbanisation. An outline of the response pathways towards sustainable and resilient cities is given as a lens to formulate informed and coherent adaptation urban planning strategies. The assessment facilitated developing a contextualised conceptual framework, focusing on demographic, climatic, and environmental changes, and the risks associated with rapid urbanisation. If not well managed in an integrated manner, rapid urbanisation poses a huge environmental and human health risk and could retard progress towards sustainable cities by 2030. Nexus planning provides the lens and basis to achieve urban resilience, by integrating complex, but interlinked sectors, by considering both ecological and built infrastructures, in a balanced manner, as key to resilience and adaptation strategies.

Operationalising the water-energy-food nexus through the theory of change.

The water-energy-food (WEF) nexus facilitates understanding of the intricate and dynamic interlinkages among the three resources. Its implementation can enhance resource securities and sustainable development. Despite its potential, full adoption of the approach has been hindered by a lack of actionable strategies to guide its practical application. This is attributed to (i) poor data (ii) lack of empirical evidence, (iii) inadequate analytical tools, and (iv) lack of clarity on applicable spatial scale. This study undertook a literature review, coupled with systemic analyses of a WEF nexus analytical model, whose outputs were used as a basis to develop a Theory of Change, an iterative outline for operationalising the approach in the context of southern Africa. The consultative and iterative Theory of Change culminated with the formulation of pathways to (i) overcome the barriers impeding WEF nexus operationalisation, (ii) mitigation of trade-offs while enhancing synergies towards attaining simultaneous resource securities, (iii) poverty alleviation and reduction of inequalities, and (iv) reconciling policy with implementation scale. The WEF nexus operationalisation outcomes are linked to Sustainable Development Goals 2 (zero hunger), 6 (clean water and sanitation), and 7 (affordable and clean energy), with synergies to SDGs 1 (no poverty), 5 (gender equality), 8 (decent work and economic growth), 12 (responsible consumption and production), 13 (climate action), 14 (life below water), and 15 (life on land). Operationalising the WEF nexus through an interactive process can inform sustainable pathways towards resource security, job and wealth creation, improved livelihoods and well-being, and regional integration.

Evaluation of Land Suitability Methods with Reference to Neglected and Underutilised Crop Species: A Scoping Review.

In agriculture, land use and land classification address questions such as "where", "why" and "when" a particular crop is grown within a particular agroecology. To date, there are several land suitability analysis (LSA) methods, but there is no consensus on the best method for crop suitability analysis. We conducted a scoping review to evaluate methodological strategies for LSA. Secondary to this, we assessed which of these would be suitable for neglected and underutilised crop species (NUS). The review classified LSA methods reported in articles as traditional (26.6%) and modern (63.4%). Modern approaches, including multi-criteria decision-making (MCDM) methods such as analytical hierarchy process (AHP) (14.9%) and fuzzy methods (12.9%); crop simulation models (9.9%) and machine learning related methods (25.7%) are gaining popularity over traditional methods. The MCDM methods, namely AHP and fuzzy, are commonly applied to LSA while crop models and machine learning related methods are gaining popularity. A total of 67 parameters from climatic, hydrology, soil, socio-economic and landscape properties are essential in LSA. Unavailability and the inclusion of categorical datasets from social sources is a challenge. Using big data and Internet of Things (IoT) improves the accuracy and reliability of LSA methods. The review expects to provide researchers and decision-makers with the most robust methods and standard parameters required in developing LSA for NUS. Qualitative and quantitative approaches must be integrated into unique hybrid land evaluation systems to improve LSA.

Spatial clustering of food insecurity and its association with depression: a geospatial analysis of nationally representative South African data, 2008-2015.

While food insecurity is a persistent public health challenge, its long-term association with depression at a national level is unknown. We investigated the spatial heterogeneity of food insecurity and its association with depression in South Africa (SA), using nationally-representative panel data from the South African National Income Dynamics Study (years 2008-2015). Geographical clusters ("hotpots") of food insecurity were identified using Kulldorff spatial scan statistic in SaTScan. Regression models were fitted to assess association between residing in food insecure hotspot communities and depression. Surprisingly, we found food insecurity hotspots (p < 0.001) in high-suitability agricultural crop and livestock production areas with reliable rainfall and fertile soils. At baseline (N = 15,630), we found greater likelihood of depression in individuals residing in food insecure hotspot communities [adjusted relative risk (aRR) = 1.13, 95% CI:1.01-1.27] using a generalized linear regression model. When the panel analysis was limited to 8,801 participants who were depression free at baseline, residing in a food insecure hotspot community was significantly associated with higher subsequent incidence of depression (aRR = 1.11, 95% CI:1.01-1.22) using a generalized estimating equation regression model. The association persisted even after controlling for multiple socioeconomic factors and household food insecurity. We identified spatial heterogeneity of food insecurity at a national scale in SA, with a demonstrated greater risk of incident depression in hotspots. More importantly, our finding points to the "Food Security Paradox", food insecurity in areas with high food-producing potential. There is a need for place-based policy interventions that target communities vulnerable to food insecurity, to reduce the burden of depression.

Biofortified Crops for Combating Hidden Hunger in South Africa: Availability, Acceptability, Micronutrient Retention and Bioavailability.

In many poorer parts of the world, biofortification is a strategy that increases the concentration of target nutrients in staple food crops, mainly by genetic manipulation, to alleviate prevalent nutrient deficiencies. We reviewed the (i) prevalence of vitamin A, iron (Fe) and zinc (Zn) deficiencies; (ii) availability of vitamin A, iron and Zn biofortified crops, and their acceptability in South Africa. The incidence of vitamin A and iron deficiency among children below five years old is 43.6% and 11%, respectively, while the risk of Zn deficiency is 45.3% among children aged 1 to 9 years. Despite several strategies being implemented to address the problem, including supplementation and commercial fortification, the prevalence of micronutrient deficiencies is still high. Biofortification has resulted in the large-scale availability of ßcarotene-rich orange-fleshed sweet potatoes (OFSP), while provitamin A biofortified maize and Zn and/or iron biofortified common beans are at development stages. Agronomic biofortification is being investigated to enhance yields and concentrations of target nutrients in crops grown in agriculturally marginal environments. The consumer acceptability of OFSP and provitamin A biofortified maize were higher among children compared to adults. Accelerating the development of other biofortified staple crops to increase their availability, especially to the target population groups, is essential. Nutrition education should be integrated with community health programmes to improve the consumption of the biofortified crops, coupled with further research to develop suitable recipes/formulations for biofortified foods.

An integrative analytical model for the water-energy-food nexus: South Africa case study.

The missing link between cross-sectoral resource management and full-scale adoption of the water-energy-food (WEF) nexus has been the lack of analytical tools that provide evidence for policy and decision-making. This study defined WEF nexus sustainability indicators, from where an analytical model was developed to manage WEF resources in an integrated manner using the Analytic Hierarchy Process (AHP). The model established quantitative relationships among WEF sectors, simplifying the intricate interlinkages among resources, using South Africa as a case study. A spider graph was used to illustrate sector performance as related to others, whose management is viewed either as sustainable or unsustainable. The model was then applied to assess progress towards the Sustainable Development Goals in South Africa. The estimated integrated indices of 0.155 and 0.203 for 2015 and 2018, respectively, classify South Africa's management of resources as marginally sustainable. The model is a decision support tool that highlights priority areas for intervention.

Optimizing Traditional Cropping Systems Under Climate Change: A Case of Maize Landraces and Bambara Groundnut.

Traditional crop species are reported to be drought-tolerant and nutrient-dense with potential to contribute to sustainable food and nutrition security within marginal production systems under climate change. We hypothesized that intercropping maize landraces (Zea mays L.) with bambara groundnut (Vigna subterranea (L.) Verdc.), together with optimum management strategies, can improve productivity and water use efficiency (WUE) under climate change. Using an ex-ante approach, we assessed climate change impacts and agronomic management options, such as plant ratios, and plant sequences, on yield and WUE of intercropped maize landrace and bambara groundnut. The Agricultural Production Systems sIMulator (APSIM) model was applied over four time periods; namely past (1961-1991), present (1995-2025), mid-century (2030-2060) and late-century (2065-2095), obtained from six GCMs. Across timescales, there were no significant differences with mean annual rainfall, but late century projections of mean annual temperature and reference crop evaporation (ET0) showed average increases of 3.5°C and 155mm, respectively. By late century and relative to the present, the projected changes in yield and WUE were -10 and -15% and 5 and 7% for intercropped bambara groundnut and maize landrace, respectively. Regardless of timescale, increasing plant population improved yield and WUE of intercropped bambara groundnut. Asynchronous planting increased yield and WUE for both maize landrace (5 and 14%) and bambara groundnut (35 and 47%, respectively). Most significant improvements were observed when either crop was planted 2-3 months apart. To reduce yield gaps in intercrop systems, low-cost management options like changing plant populations and sequential cropping can increase yield and WUE under projected climate change. To further increase sustainability, there is a need to expand the research to consider other management strategies such as use of other traditional crop species, fertilization, rainwater harvesting and soil conservation techniques.

Bambara groundnut: an exemplar underutilised legume for resilience under climate change.

MAIN CONCLUSION: Bambara groundnut has the potential to be used to contribute more the climate change ready agriculture. The requirement for nitrogen fixing, stress tolerant legumes is clear, particularly in low input agriculture. However, ensuring that existing negative traits are tackled and demand is stimulated through the development of markets and products still represents a challenge to making greater use of this legume. World agriculture is currently based on very limited numbers of crops, representing a significant risk to food supplies, particularly in the face of climate change which is expected to increase the frequency of extreme events. Minor and underutilised crops can help to develop a more resilient and nutritionally dense future agriculture. Bambara groundnut [Vigna subterranea (L.) Verdc.[, as a drought resistant, nitrogen-fixing, legume has a role to play. However, as with most underutilised crops, there are significant gaps in knowledge and also negative traits such as 'hard-to-cook' and 'photoperiod sensitivity to pod filling' associated with the crop which future breeding programmes and processing methods need to tackle, to allow it to make a significant contribution to the well-being of future generations. The current review assesses these factors and also considers what are the next steps towards realising the potential of this crop.

Climate Change Adaptation through the Water-Energy-Food Nexus in Southern Africa.

Climate change is a complex and cross-cutting problem that needs an integrated and transformative systems approach to respond to the challenge. Current sectoral approaches to climate change adaptation initiatives often create imbalances and retard sustainable development. Regional and international literature on climate change adaptation opportunities and challenges applicable to southern Africa from a water-energy-food (WEF) nexus perspective was reviewed. Specifically, this review highlights climate change impacts on water, energy, and food resources in southern Africa, while exploring mitigation and adaptation opportunities. The review further recommends strategies to develop cross-sectoral sustainable measures aimed at building resilient communities. Regional WEF nexus related institutions and legal frameworks were also reviewed to relate the WEF nexus to policy. Southern Africa is witnessing an increased frequency and intensity in climate change-associated extreme weather events, causing water, food, and energy insecurity. A projected reduction of 20% in annual rainfall by 2080 in southern Africa will only increase the regional socio-economic challenges. This is exacerbating regional resource scarcities and vulnerabilities. It will also have direct and indirect impacts on nutrition, human well-being, and health. Reduced agricultural production, lack of access to clean water, sanitation, and clean, sustainable energy are the major areas of concern. The region is already experiencing an upsurge of vector borne diseases (malaria and dengue fever), and water and food-borne diseases (cholera and diarrhoea). What is clear is that climate change impacts are cross-sectoral and multidimensional, and therefore require cross-sectoral mitigation and adaptation approaches. In this regard, a well-coordinated and integrated WEF nexus approach offers opportunities to build resilient systems, harmonise interventions, and mitigate trade-offs and hence improve sustainability. This would be achieved through greater resource mobilisation and coordination, policy convergence across sectors, and targeting nexus points in the landscape. The WEF nexus approach has potential to increase the resilience of marginalised communities in southern Africa by contributing towards attaining the Sustainable Development Goals (SDGs 1, 2, 3, 6, 7, and 13).

The Potential of Integrating Provitamin A-Biofortified Maize in Smallholder Farming Systems to Reduce Malnourishment in South Africa.

Biofortification interventions have the potential to combat malnutrition. This review explored the use of provitamin A-biofortified maize (PVABM) as a vitamin A deficiency (VAD) reduction agricultural-based strategy. Maize has been identified as one of the key staple crops for biofortification to reduce hidden hunger in Africa. Most nutrition interventions have not been successful in reducing hunger because rural communities, who mainly rely on agriculture, have been indirectly excluded. The biofortification intervention proposed here aims to be an inclusive strategy, based on smallholder farming systems. Vitamin A is a micronutrient essential for growth, immune function, reproduction and vision, and its deficiency results in VAD. VAD is estimated to affect more than 250 million children in developing countries. In Africa, especially sub-Saharan Africa, maize is a staple food for rural communities, consumed by most household members. Due to carotenoids, PVABM presents an orange color. This color has been reported to lead to negative perceptions about PVABM varieties. The perceived agronomic traits of this maize by smallholder farmers have not been explored. Adoption and utilization of PVABM varieties relies on both acceptable consumer attributes and agronomic traits, including nutritional value. It is therefore important to assess farmers' perceptions of and willingness to adopt the varieties, and the potential markets for PVABM maize. It is essential to establish on-farm trials and experiments to evaluate the response of PVABM under different climatic conditions, fertilizer levels and soils, and its overall agronomic potential. For the better integration of PVABM with smallholder farming systems, farmer training and workshops about PVABM should be part of any intervention. A holistic approach would enhance farmers' knowledge about PVABM varieties and that their benefits out-compete other existing maize varieties.

Developing a Roadmap for Improving Neglected and Underutilized Crops: A Case Study of South Africa.

Reports of neglected and underutilized crops' (NUS) potential remain mostly anecdotal with limited and often incoherent research available to support them. This has been attributed to lack of clear research goals, limited funding directed at NUS and journal apathy toward publishing work on NUS. The latter points also explain the lack of interest from emerging and established researchers. Additionally, the NUS community's inability to articulate a roadmap for NUS' promotion may have unintentionally contributed to this. The current study is a sequel to an initial study that assessed the status of NUS in South Africa. The objective of this follow-up study was then to (i) identify priority NUS, and (ii) articulate a strategy and actionable recommendations for promoting NUS in South Africa. The study identified 13 priority NUS, categorized into cereals, legumes, root, and tuber crops and leafy vegetables based on drought and heat stress tolerance and nutritional value. It is recommended that the available limited resources should be targeted on improving these priority NUS as they offer the best prospects for success. Focus should be on developing value chains for the priority NUS. This should be underpinned by science to provide evidence-based outcomes. This would assist to attract more funding for NUS research, development and innovation in South Africa. It is envisaged that through this roadmap, NUS could be transformed from the peripheries into mainstream agriculture. This study provides a template for developing a roadmap for promoting NUS that could be transposed and replicated among the 14 other southern African states.

The Potential Role of Neglected and Underutilised Crop Species as Future Crops under Water Scarce Conditions in Sub-Saharan Africa.

Modern agricultural systems that promote cultivation of a very limited number of crop species have relegated indigenous crops to the status of neglected and underutilised crop species (NUCS). The complex interactions of water scarcity associated with climate change and variability in sub-Saharan Africa (SSA), and population pressure require innovative strategies to address food insecurity and undernourishment. Current research efforts have identified NUCS as having potential to reduce food and nutrition insecurity, particularly for resource poor households in SSA. This is because of their adaptability to low input agricultural systems and nutritional composition. However, what is required to promote NUCS is scientific research including agronomy, breeding, post-harvest handling and value addition, and linking farmers to markets. Among the essential knowledge base is reliable information about water utilisation by NUCS with potential for commercialisation. This commentary identifies and characterises NUCS with agronomic potential in SSA, especially in the semi-arid areas taking into consideration inter alia: (i) what can grow under water-scarce conditions, (ii) water requirements, and (iii) water productivity. Several representative leafy vegetables, tuber crops, cereal crops and grain legumes were identified as fitting the NUCS category. Agro-biodiversity remains essential for sustainable agriculture.