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Field experiments were carried out during the summer/autumn (first trial) and winter/spring (second trial) seasons of 2019 and 2021 in the Dlangubo, Ngwelezane, and Mtubatuba areas of KwaZulu-Natal Province of South Africa to study the drought amelioration effects and impact of two locally available organic wastes (filter cake—a residue derived from sugar cane filtration (FC) and macadamia husk compost (MHC)) on the productivity and physiological responses of four orange-fleshed sweet potato cultivars (Beauregard cv., Impilo, W-119 and 199062.1). The effects of FC and MHC were compared with that of inorganic fertilizer (IF) [2:3:2 (30)], FC + IF, MHC + IF, and the control. The soil amendments were applied in the first trials only. Climatic data such as humidity, temperature, and rainfall were taken via remote sensing. The results of the first trial indicated that filter cake and IF significantly performed better than MHC. The strength of filter cake may be attributable to its rich array of mineral nutrients such as calcium, magnesium, potassium, sodium, zinc, copper, manganese, iron, and phosphorus. The limited performance of MHC may be attributable to its ability to hold water. Furthermore, a positive correction occurred between the yield of the test orange-fleshed sweet potato (OFSP) cultivars, rainfall, and vegetation indices (normalized difference vegetation index, enhanced vegetation index, and normalized difference water index) investigated in the study. In season two, IF treatment did not have any significant effect on the growth and productivity of any of the tested sweet potato cultivars, but, FC, FC + IF, and MHC treatments largely maintained their performances. In conclusion, the use of FC is highly recommended in the production of the test OFSP cultivars. Furthermore, the study indicates that both FC and MHC may not only supply the needed plant nutrients but has the capacity to reduce the impact of drought on the growth of the test cultivars. These findings are of great value to farmers, especially the resource-poor ones. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

• WEF nexus sustainability indicators are a means of assessing resource management in an integrated manner. • The developed model eliminated "a silo" approach in resource development by assessing resource management as a single unit. • The model has established numerical relationships among the WEF nexus, indicating priority areas for intervention. • The model assessed the progress towards achieving related SDGs to achieve sustainability by 2030. 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Highlights: [•] AquaCrop was successfully parameterised for a South African taro landrace. [•] Calibration and validation of AquaCrop were successful. [•] AquaCrop model was able to simulate growth and yield of taro under varying water and environmental conditions. [•] The model is simple and could be easily used for technology transfer. [Copyright &y& Elsevier]

Reference 1 Mugiyo H, Chimonyo VGP, Sibanda M, Kunz R, Nhamo L, Masemola CR, et al. (2021) Multi-criteria suitability analysis for neglected and underutilised crop species in South Africa. There is an error in the seventh author's name. [Extracted from the article]

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 βcarotene-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. [ABSTRACT FROM AUTHOR]

Water productivity (WP) is becoming a key issue in understanding the relationship between water availability and rainfed sorghum (Sorghum bicolor L. Moench) yields in agricultural systems across sub–Saharan Africa. The objective of this study was to determine water productivity of three sorghum genotypes under different environmental conditions. Three sorghum genotypes, a hybrid (PAN8816), a commercial open-pollinated variety (Macia) and a landrace (Ujiba) were planted at two sites (Ukulinga and Mbumbulu) in South Africa during 2013/2014 and 2014/2015. High clay content in Mbumbulu lowered plant available water in the soil compared to Ukulinga. Sorghum adapted to low water availability by significantly (P < 0.05) lowering plant growth (green leaf number, plant height and canopy cover), crop physiology (chlorophyll content index and stomatal conductance), biomass and grain yield. Ujiba and PAN8816 genotypes hastened phenological development, whilst Macia delayed phenological development in response to low water availability. Total and grain WP were lower at Mbumbulu (14.93 and 7.49 kg/ha/mm) relative to Ukulinga (21.49 and 11.01 kg/ha/mm), respectively. Results showed that Macia had significantly higher (P < 0.05) WP (10.51 kg/ha/mm) relative to PAN8816 (9.34 kg/ha/mm) and Ujiba (7.90 kg/ha/mm). Lack of significant genotypic differences in grain WP highlights that all three genotypes are equally suitable for production under sub–optimal and dryland conditions. [ABSTRACT FROM AUTHOR]

Deals with a study which provided evidence that a traditional approach to maize storage used by some subsistence farmers in South Africa has merit for agriculture and possibly germ-plasm preservation. Background of the study; Methods and results.

Nationally recommended sorghum planting dates in South Africa are inaccurate since they are similar for all sorghum growing regions, irrespective of climatic and soil variations within agro-ecological regions The objective was to apply a well–calibrated and tested AquaCrop model to formulate optimal planting dates and best practice management recommendations for rainfed sorghum production in three different agro–ecologies of KwaZulu–Natal, South Africa (Ukulinga, Deepdale, and Richards Bay). The FAO AquaCrop model was used to generate 10 planting dates for the different agro–ecologies. Crop files for two sorghum genotypes Ujiba (landrace) and PAN8816 (hybrid) were used for model simulations, where 10 year historical climate data was considered. Seasonal rainfall, amount of soil evaporation, crop transpired water, and ground canopy cover were identified as key parameters influencing sorghum biomass, yield and water productivity. The following optimal dates were identified at Ukulinga (7 September - 24 November), Richards Bay (23 December - 3 January), and Deepdale (21 December - 3 January). These were recommended to update generic national recommendations for sorghum for agro-ecologies represented by the respective sites. High soil evaporation relative to transpiration in all agro-ecologies indicated that the low hanging fruit in improving sorghum yields was strategies use of strategies that reduce soil evaporation and increase soil water retention. Further research can look at calibrating and validating AquaCrop for best practice management recommendations suggested in this study to predict with accuracy the impact of such strategies on yield and water productivity of sorghum in various agro-ecologies. • Optimal sorghum planting dates at Ukulinga agro-ecological site were between 7 September and 24 November. • Optimal sorghum planting dates at Richard's Bay agro-ecological site were between 23 December and 3 January. • Optimal sorghum planting dates at Deepdale agro-ecological site were between 21 December and 3 January. • Rainfall was high but variable Richards Bay resulting in high soil evaporation, low transpiration and low crop yields. • Yields at Ukulinga and Deepdale were high due to high transpiration and relatively low evaporative demand. [ABSTRACT FROM AUTHOR]

The challenges emanating from the rapid urbanisation of the Gauteng City-Region in South Africa require innovative strategies to transform the urbanised province into a climate action and adaptation centre. We provide an analysis of the impacts of rapid urbanisation in the Gauteng City-Region, highlighting major challenges related to (i) land use management, (ii) service delivery (water, energy, food, and waste and sanitation), and (iii) social cohesion, applying geospatial techniques to assess spatio-temporal changes and variations in land surface temperatures. Massive impervious surfaces, rising temperatures, flooding and heatwaves are compounding the challenges associated with rapid urbanisation in the city region. We provide an outline of the response pathways towards a sustainable and resilient city-region and inform policy on formulating coherent adaptation urban planning strategies. If not well managed, rapid urbanisation could be a huge environmental and human health risk and a threat to sustainable cities by 2030. Nexus planning is proposed to provide the basis to achieve urban resilience as it integrates distinct, but interlinked sectors, considering both ecological and built infrastructures, in a balanced and integrated manner. • Nexus planning provides the lens and basis to achieve urban resilience in an integrated manner. • Urban nexus guides the formulation of informed and coherent adaptation urban planning strategies. • The developed urban nexus framework provides pathways towards sustainable cities. • Urban areas can become centres for sustainable socio-economic development and for climate action and adaptation. [ABSTRACT FROM AUTHOR]