Integrated assessment of climate change impacts on crop productivity and income of commercial maize farms in northeast South Africa

Assessing Commercial Sugarcane Irrigators’ Intentions to Adapt Water-Use Behaviour in Response to Climate Variability in South Africa

The scarcity of water resources in South Africa remains a considerable challenge for water users. This study evaluated the impact of climate variability on the adaptive water-use behaviour of sugarcane producers by identifying the factors influencing their adaptation decisions. A survey, the Theory of Planned Behaviour (TPB), and structural equation modelling (SEM) were used to achieve this objective. The study involved 54 sugarcane producers from the Impala Irrigation Scheme, selected through random sampling. Socio-economic profiles revealed a largely male, older demographic with varied education levels and farm characteristics. Results indicated that attitude (β = 0.349, p < 0.1) and subjective norms (β = 0.281, p < 0.05) significantly influenced farmers’ intentions to adapt, while perceived behavioural control had no significant effect (β = 0.051, p > 0.1). These findings suggest that improving farmers’ attitudes and strengthening social support systems can enhance their intentions to adopt adaptive strategies. However, the model’s explanatory power (R² = 0.276) suggests that other unexamined factors may also influence farmers’ adaptive intentions, highlighting the need for further research. Overall, our findings suggest that interventions targeting attitudes, social support, and resource access can improve adaptive behaviours.

A systematic literature review on the impact of climate change on the livelihoods of smallholder farmers in South Africa

Smallholder farmers in South Africa are increasingly vulnerable to the adverse effects of climate change, posing significant threats to their livelihoods and food security. This systematic literature review investigates the several impacts of climate change on smallholder farmers across the country. The literature review used a systematic approach to search for relevant research across three academic databases such as Google scholar, Consensus, and Zendy. Based on the inclusion criteria for the literature review, 261 articles were initially screened, and 35 articles were included in the systematic review. This process helped to identify the most relevant and high-quality studies on the topic. The data extracted from the 35 articles were analyzed and synthesized to identify the impact of climate change on the livelihoods of smallholder farmers. This helped to identify commonalities and differences across the literature, and to draw conclusions about the impact of climate change on the livelihoods of smallholder farmers. The study identified and examined the specific challenges faced by smallholder farmers, including the loss of livestock, reduced crop yields and heightened economic hardship. Additionally, the review explores the coping strategies employed by farmers to mitigate these challenges and adapt to the evolving climatic conditions. The findings highlight the urgent need for targeted interventions and support mechanisms aimed at enhancing the resilience of smallholder farmers and ensuring the long-term sustainability of agricultural practices amidst the challenges posed by climate change. Furthermore, the study provides valuable recommendations for policymakers, agriculturalists, and other stakeholders to address the identified issues and support smallholder farmers in adapting to climate change.

Nexus between summer climate variability and household food security in rural Mpumalanga Province, South Africa

Ongoing climate changes are likely to impact household food security in rural households that depend on rainfed subsistence agriculture. This paper investigates the relationship between summer climate variability and household food security in rural Mpumalanga, South Africa. We used a household panel data set nested in the Agincourt Health and Socio-Demographic Surveillance System, together with rainfall and temperature data for the summer periods 2006-07 to 2018-19 from three weather stations that surround the study area. We quantified the variability of rainfall using coefficient of variation and the standardized rainfall anomaly index, while temperature variability was reflected by the standardised temperature anomaly. In addition, the Mann-Kendall analysis was applied to detect temporal trends in rainfall and temperature. Longitudinal models accounting for socioeconomic and climate factors were used to estimate the relationship between weather and climate. The results reveal significant impact on food security from high inter-annual rainfall variability through fluctuations in food consumption, dietary diversity, and the experience of hunger. This study offers significant insights on how dietary diversity, food availability and overall food security are positively associated with greater average rainfall through subsistence agriculture as a livelihood strategy. These insights have important implications by suggesting seasonal forecasts to predict periods of potential food insecurity in local communities and can guide government policy and interventions to lessen food insecurity in rural areas.

Drought patterns: their spatiotemporal variability and impacts on maize production in Limpopo province, South Africa

Due to global climate change, droughts are likely to become more frequent and more severe in many regions such as in South Africa. In Limpopo, observed high climate variability and projected future climate change will likely increase future maize production risks. This paper evaluates drought patterns in Limpopo at two representative sites. We studied how drought patterns are projected to change under future climatic conditions as an important step in identifying adaptation measures (e.g., breeding maize ideotypes resilient to future conditions). Thirty-year time horizons were analyzed, considering three emission scenarios and five global climate models. We applied the WOFOST crop model to simulate maize crop growth and yield formation over South Africa's summer season. We considered three different crop emergence dates. Drought indices indicated that mainly in the scenario SSP5-8.5 (2051-2080), Univen and Syferkuil will experience worsened drought conditions (DC) in the future. Maize yield tends to decline and future changes in the emergence date seem to impact yield significantly. A possible alternative is to delay sowing date to November or December to reduce the potential yield losses. The grain filling period tends to decrease in the future, and a decrease in the duration of the growth cycle is very likely. Combinations of changed sowing time with more drought tolerant maize cultivars having a longer post-anthesis phase will likely reduce the potential negative impact of climate change on maize.

Co-inventions, uncertainties and global food security

This paper examines the effects of international collaborative efforts on climate-friendly agricultural technologies on global food security. In particular, we use patent data on environmental technological innovations for OECD countries and global food prices from the period 1990 to 2016. Also, we investigate the impact of uncertainties in weather conditions in terms of rising global temperature created by climate change using data on global surface temperature from the Energy Information Administration and the Goddard Institute for Space Studies (GISS) Surface Temperature Analysis of the National Aeronautics and Space Administration (NASA). We used both impulse response functions and variance error decomposition from a panel Vector Auto-Regressive (VAR) model to examine both the response of global food prices to shocks on the concerned variables and the decomposition of error variance in global food prices. First, our results show that international collaborative efforts on climate-friendly agricultural technologies reduce global food prices while increasing global surface temperature increases food prices. Regarding the variance decomposition of global food prices, results show that surface temperature followed by international collaborations in climate-friendly innovations and other environment-related technologies are the main drivers of forecast error variance in global food prices. The food price variance share associated with greenhouse gas emissions is less when compared to that of technological innovations.

Constraints and Prospects of Improving Cowpea Productivity to Ensure Food, Nutritional Security and Environmental Sustainability

Providing safe and secure food for an increasing number of people globally is challenging. Coping with such a human population by merely applying the conventional agricultural production system has not proved to be agro-ecologically friendly; nor is it sustainable. Cowpea (Vigna unguiculata (L) Walp) is a multi-purpose legume. It consists of high-quality protein for human consumption, and it is rich in protein for livestock fodder. It enriches the soil in that it recycles nutrients through the fixation of nitrogen in association with nodulating bacteria. However, the productivity of this multi-functional, indigenous legume that is of great value to African smallholder farmers and the rural populace, and also to urban consumers and entrepreneurs, is limited. Because cowpea is of strategic importance in Africa, there is a need to improve on its productivity. Such endeavors in Africa are wrought with challenges that include drought, salinity, the excessive demand among farmers for synthetic chemicals, the repercussions of climate change, declining soil nutrients, microbial infestations, pest issues, and so forth. Nevertheless, giant strides have already been made and there have already been improvements in adopting sustainable and smart biotechnological approaches that are favorably influencing the production costs of cowpea and its availability. As such, the prospects for a leap in cowpea productivity in Africa and in the enhancement of its genetic gain are good. Potential and viable means for overcoming some of the above-mentioned production constraints would be to focus on the key cowpea producer nations in Africa and to encourage them to embrace biotechnological techniques in an integrated approach to enhance for sustainable productivity. This review highlights the spectrum of constraints that limit the cowpea yield, but looks ahead of the constraints and seeks a way forward to improve cowpea productivity in Africa. More importantly, this review investigates applications and insights concerning mechanisms of action for implementing eco-friendly biotechnological techniques, such as the deployment of bio inoculants, applying climate-smart agricultural (CSA) practices, agricultural conservation techniques, and multi-omics smart technology in the spheres of genomics, transcriptomics, proteomics, and metabolomics, for improving cowpea yields and productivity to achieve sustainable agro-ecosystems, and ensuring their stability.

Assessing South Africa's institutional adaptive capacity to maize production in the context of climate change: Integration of a socioeconomic development dimension

The deployment of adaptation plans to limit the threat of climate change often hinges on the capacity of various national and local institutions. An observed decline in South Africa's maize production over the last few decades has raised questions about the capacity of institutions responsible for providing climate change-related adaptive support to maize farmers in the country. This study assessed the adaptive capacity of management institutions in South Africa supporting maize producers, using a combination of literature review, document analysis, and in-depth interviews applied in the adaptive capacity wheel (ACW) assessment tool. On the basis of the results obtained from this analysis, the adaptive capacity of South African institutions responsible for climate change response processes was scored as medium. Findings from the research suggest that the advances made to date in South Africa in terms of climate change-related policy development, resource allocation, and capacity development could be inadequate, given the extent of identified institutional weaknesses, capacity constraints, knowledge, and information limitations. The study concludes that an inability to address current institutional limitations, considering the threats associated with climate change, may result in intensified social and economic challenges in the maize production sector. The study recommends the consistent revision and capacitation of these institutions to enable them to provide the type of support that will ensure effective adaptive responses for farmers involved in maize production in the country. Integr Environ Assess Manag 2021;17:1056-1069. © 2021 SETAC.

Estimation of Evapotranspiration and Water Requirements of Strawberry Plants in Greenhouses Using Environmental Data

Farmers routinely determine irrigation requirements from visual observations and cultivation experience, but this can lead to under- or over-irrigation. To establish precise irrigation technology for strawberry cultivation, the average daily evapotranspiration and water requirements were estimated according to the environmental data: air temperature and humidity from the center of the greenhouses and solar radiation from outside greenhouses. Makkink FAO24 equations (temperature and cloudiness) were used to estimate the evapotranspiration and water requirements. The temperature equation showed higher correlation coefficients in solar radiation (R2 = 0.60), evapotranspiration (R2 = 0.76), and water requirements (R2 = 0.69) than other tested equations. The daily irrigation, calculated from the estimated evapotranspiration, was 3.8 tons/10a. It is possible to develop a precision irrigation system from estimated evapotranspiration during the winter cultivation of “Seolhyang” strawberries in South Korea.

Modeling the potential impacts of climate change and adaptation strategies on groundnut production in India

Groundnut is one of the significant sources of oil, food, and fodder in India. It is grown in marginal arid and semi-arid agro-ecosystems with wide yield fluctuations due to spatial variability of rainfall and soil. Climate change, which is predicted to increase the intra- and inter-annual rainfall variability will further constrain the groundnut economy in India besides the global and domestic economic, social and policy changes. Through this study we aim to examine the biophysical and social economic impacts of climate change on groundnut production and prices to provide a comprehensive analysis of how agriculture and the food system will be affected. Using projected climate data for India, we estimated the biophysical impacts of climate change on groundnut during mid-century using representative concentration pathway (RCP 8.5) scenario. We examined the impacts of changes in population and income besides environmental factors on groundnut productivity. This is to highlight the importance of holistic assessment of biophysical and socioeconomic factors to better understand climate change impacts. Modelled projections show that by 2050, climate change under an optimistic scenario will result in −2.3 to 43.2% change in groundnut yields across various regions in India when climate alone was factored in. But the change in groundnut yields ranged from −0.9% to 16.2% when economic (population and income) and market variables (elasticities, trade, etc.) were also considered. Similarly, under pessimistic climate change scenario, the percent change in groundnut yields would be −33.7 to 3.4 with only the climate factored in and −11.2 to 4.3 with the additional economic and market variables included. This indicates the sensitivity of climate change impacts to differences in socioeconomic factors. This study highlights the need to take into account market effects to gain a holistic understanding of how economic and environmental factors impact agricultural food systems and economies.

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Projected climate change will impact groundnut yields by −34 to 43% across India.

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Adaptation synergies developed showed promising in adverse climate conditions.

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Biophysical and economic model integration is crucial for assessment of climate change.

Impacts of Agroclimatic Variability on Maize Production in the Setsoto Municipality in the Free State Province, South Africa

The majority of people in South Africa eat maize, which is grown as a rain-fed crop in the summer rainfall areas of the country, as their staple food. The country is usually food secure except in drought years, which are expected to increase in severity and frequency. This study investigated the impacts of rainfall and minimum and maximum temperatures on maize yield in the Setsoto municipality of the Free State province of South Africa from 1985 to 2016. The variation of the agroclimatic variables, including the Palmer stress diversity index (PSDI), was investigated over the growing period (Oct–Apr) which varied across the four target stations (Clocolan, Senekal, Marquard and Ficksburg). The highest coefficients of variance (CV) recorded for the minimum and maximum temperatures and rainfall were 16.2%, 6.2% and 29% during the growing period. Non-parametric Mann Kendal and Sen’s slope estimator were used for the trend analysis. The result showed significant positive trends in minimum temperature across the stations except for Clocolan where a negative trend of 0.2 to 0.12 °C year−1 was observed. The maximum temperature increased significantly across all the stations by 0.04–0.05 °C year−1 during the growing period. The temperature effects were most noticeable in the months of November and February when leaf initiation and kernel filling occur, respectively. The changes in rainfall were significant only in Ficksburg in the month of January with a value of 2.34 mm year−1. Nevertheless, the rainfall showed a strong positive correlation with yield (r 0.46, p = < 0.05). The overall variation in maize production is explained by the contribution of the agroclimatic parameters; the minimum temperature (R2 0.13–0.152), maximum temperature (R2 0.214–0.432) and rainfall (R2 0.17–0.473) for the growing period across the stations during the study period. The PSDI showed dry years and wet years but with most of the years recording close to normal rainfall. An increase in both the minimum and maximum temperatures over time will have a negative impact on crop yield.