Promoting climate-smart sustainable agroforestry to tackle social and environmental challenges: The case of macadamia agroforestry in Malawi

Our current global food system is understood to require a fundamental transformation based on a holistic approach to maintain long-term fertility, healthy biodiverse agroecosystems, and climate-proof/secure livelihoods. Recently, there has been a growing recognition of smallholder farmers’ contributions to addressing key global environmental and social development issues, including poverty, food security, climate change, and sustainable development. One specific approach is agroforestry-based agriculture, in which edible food and commercially important trees are grown on cropland, thereby improving the biodiversity of farming systems, enhancing agricultural productivity, and adding benefits such as nutrition and financial stability, not least climate resilience. In this context, we present lessons learned from an agroforestry system in Malawi that involves smallholder farmer cooperatives interplanting macadamia nut trees with annual crops such as groundnuts, maize, and soybeans. We review holistic advantages such as yield improvement, farmer perceptions, and challenges. We provide insights into what works in designing (Neno Macadami Trust and linkage with finance plan) and draw lessons that can be applied to other comparable programmes worldwide

Comprehensive assessment of soil and dust heavy metal(loid)s exposure scenarios at residential playgrounds in Beijing, China

Small playgrounds situated within residential communities are popular recreational areas. However, heavy metal(loid)s (HMs) in soil or equipment dust may pose a public health risk. This study provides a comprehensive assessment of the health risk associated with HMs exposure at residential playgrounds in cities, a field that has not been thoroughly investigated previously. 70 soil and 70 equipment dust samples were collected from 30 urban and 40 suburban playgrounds in Beijing. Results indicated significant enrichment of Cu, As, and Ni in the soil with Enrichment Factors (EFs) >5 from both anthropogenic and lithogenic sources. Correlation analyses showed that the levels of Be, Cr, Mn, Co, Ni in soil and Be, Mn, As, Cd in dust were positively correlated with the distance to the nearest highway, with p-values < 0.01. Enrichment and correlation analyses contributed to a better understanding of the sources and transport pathways of HMs in urban environment. Based on a site-specific Conceptual Site Model (CSM), the carcinogenic risks (CRs) and Hazard Quotients (HQs) were quantified for residents as the ratio of HMs exposure to reference doses. Risk assessment indicated the mean predicted CR for children and adults exposed to soil was 3.75 × 10−6 and 5.29 × 10−6, respectively, while that at dust exposure scenarios was lower, at 2.47 × 10−6 and 3.49 × 10−6, respectively, all of which were at the upper end of U.S. EPA's acceptable criteria of 1 × 10−6 to 1 × 10−4. Among the HMs, As and Ni were identified as the priority control contaminants due to significant contribution to CRs. Furthermore, the spatial distribution revealed an increasing trend in health risk from the urban center to the suburbs. This study emphasizes the need for effective measures to mitigate potential health risk and enhance the safety of recreational areas, particularly for susceptible individuals

Evaluation of cardiopreventive effects of Ximenia americana (Linn.) and Pappea capensis (Eckl. and Zeyh.) leaf aqueous extracts in rat models with myocardial infarction

Background Myocardial infarction is a significant health issue in both wealthy and underdeveloped nations. Globally, it is the leading cause of deaths among cardiovascular diseases. In 2012, myocardial infarction-related deaths were about 14.1 million out of 17.5 million cardiovascular disease-related deaths. Clinical management of myocardial infarction remains a challenge because most conventional drugs provide symptomatic relief only. In addition, conventional remedies are associated with numerous advese effects and arguably, in many cases are quite expensive. Hence, herbal remedies, which are widely available, with comparatively fewer side effects, and are affordable, provide a more attractive therapeutic alternative. This study aimed at determining cardiopreventive effects of aqueous leaf extracts of X. americana and P. capensis. Phytochemical screening was done using liquid chromatography-mass spectrometry. Wistar albino rats were employed to test for cardiopreventive effects of the extracts and were randomized into 6 groups of 5 animals each. Groups I, II, and III were normal, negative, and positive controls, respectively, and rats were given normal saline, salbutamol (7.5 mg/Kg bw), and propranolol, respectively. Groups IV, V, and VI rats were treated with extracts dose levels 50, 100, and 150 mg/Kg bw, respectively. Biochemical analysis was done to determine effects of the extracts on levels of serum cardiac troponin T, creatine kinase-MB, lactate dehydrogenase-1, and lipid profiles. Levels of oxidative stress markers were determined in the heart tissue. Results The LC–MS analysis revealed different phytocompounds in the extracts, including flavonoids, phenolic acids, glycosides and tannins, which are known to confer cardioprotective activities. The extracts significantly prevented increase in cardiac troponin T, creatine kinase-MB, lactate dehydrogenase-1, total cholesterol, triglycerides, LDL, and MDA levels, as well as a significant increase in superoxide dismutase, catalase, glutathione peroxidase, and HDL levels. Conclusions This study confirmed that Ximenia americana and Pappea capensis extracts have the potential to prevent myocardial infarction in rats. Generally, P. capensis extract showed better activity as compared to X. americana extract. The effects of the extracts could be attributable to the presence of various cardioactive phytocompounds. Therefore, these plants can be considered in the development of potent and safe cardiopreventive drugs

Sustainable remediation and redevelopment of brownfield sites

Anthropogenic activities have caused widespread land contamination, resulting in the degradation and loss of productive land, deterioration of ecological systems, and detrimental human health effects. To provide land critical for future sustainable development, remediation and redevelopment of the estimated 5 million global brownfield sites is thus needed. In this Review, we outline sustainable remediation strategies available for the cleanup of contaminated soil and groundwater at brownfield sites. Conventional remediation strategies, such as dig & haul and pump & treat, ignore externalities including secondary environmental burden and socioeconomic impacts such that their life cycle detrimental impact can exceed their benefit. However, a range of sustainable remediation technologies offer opportunities for urban revitalization, including sustainable immobilization, low-impact bioremediation, novel in-situ chemical treatment, and innovative passive barriers. These approaches can substantially reduce life cycle environmental footprints, increase the longevity of functional materials, alleviate potential toxic by-products, and maximize overall net benefits. Moreover, the integration of remediation and redevelopment through deployment of nature-based solutions and sustainable energy systems could render substantial social and economic benefits. While sustainable remediation will shape brownfield development for years to come, ethics and equality are almost never considered in assessment tools, and long-term resilience needs to be addressed

Metabolomics reveals the response of hydroprimed maize to mitigate the impact of soil salinization

Soil salinization is a major environmental stressor hindering global crop production. Hydropriming has emerged as a promising approach to reduce salt stress and enhance crop yields on salinized land. However, a better mechanisitic understanding is required to improve salt stress tolerance. We used a biochemical and metabolomics approach to study the effect of salt stress of hydroprimed maize to identify the types and variation of differentially accumulated metabolites. Here we show that hydropriming significantly increased catalase (CAT) activity, soluble sugar and proline content, decreased superoxide dismutase (SOD) activity and peroxide (H2O2) content. Conversely, hydropriming had no significant effect on POD activity, soluble protein and MDA content under salt stress. The Metabolite analysis indicated that salt stress significantly increased the content of 1278 metabolites and decreased the content of 1044 metabolites. Ethisterone (progesterone) was the most important metabolite produced in the roots of unprimed samples in response to salt s tress. Pathway enrichment analysis indicated that flavone and flavonol biosynthesis, which relate to scavenging reactive oxygen species (ROS), was the most significant metabolic pathway related to salt stress. Hydropriming significantly increased the content of 873 metabolites and significantly decreased the content of 1313 metabolites. 5-Methyltetrahydrofolate, a methyl donor for methionine, was the most important metabolite produced in the roots of hydroprimed samples in response to salt stress. Plant growth regulator, such as melatonin, gibberellin A8, estrone, abscisic acid and brassinolide involved in both treatment. Our results not only verify the roles of key metabolites in resisting salt stress, but also further evidence that flavone and flavonol biosynthesis and plant growth regulator relate to salt tolerance

Threat or opportunity? An analysis of perceptions of cultured meat in the UK farming sector

The environmental and social impacts of cultured meat, and its economic viability, are contingent on its implications for food production and for agriculture. However, the implications of cultured meat production for farmers have not yet been thoroughly investigated and are poorly understood. The aim of this research was to engage with the farming sector in critically assessing cultured meat as a technology which could profoundly affect future farm livelihoods, land use, rural and farming communities and agricultural value chains. Ensuring farmers' voices, and potential 'counternarratives' inform the development of cultured meat is not only inclusive, but could identify unexpected impacts of this emerging technology and contribute to the framing of the social license of the industry developing them.Six focus groups were undertaken with 75 UK farmers from a variety of farming sectors and regions. Questions focused on what the term 'cultured meat' means to farmers, the potential impacts of cultured meat, and potential business scenarios arising for farmers. All meetings were recorded, transcribed, and thematically analyzed.Farmers expressed complex and considered reflections on cultured meat, raising several perceived opportunities and risks associated with the themes of 'ethics and affective' narratives, 'environmentbased' narratives, and 'socio-economic' narratives. Aspects of foci of power, food system control and transparency associated with cultured meat emerged from the conversations, as well as cultured meat's potential impacts on the environment and on jobs, farming/rural communities and connecting with the land.Globally, meat production underpins the livelihoods of many rural communities, so a transition to cultured meat is likely to have deep-seated ethical, environmental, and socio-economic impacts. Within the discourse on cultured meat the voices of farmers are often lost. While not claiming to be representative of all UK farming, this study engaged UK farmer perspectives as a way of starting the substantive process of greater stakeholder inclusion in cultured meat innovation pathways, and which should underpin responsible technology transitions in agriculture

Contaminant containment for sustainable remediation of persistent contaminants in soil and groundwater

Contaminant containment measures are often necessary to prevent or minimize offsite movement of contaminated materials for disposal or other purposes when they can be buried or left in place due to extensive subsurface contamination. These measures can include physical, chemical, and biological technologies such as impermeable and permeable barriers, stabilization and solidification, and phytostabilization. Contaminant containment is advantageous because it can stop contaminant plumes from migrating further and allow for pollutant reduction at sites where the source is inaccessible or cannot be removed. Moreover, unlike other options, contaminant containment measures do not require the excavation of contaminated substrates. However, contaminant containment measures require regular inspections to monitor for contaminant mobilization and migration. This review critically evaluates the sources of persistent contaminants, the different approaches to contaminant remediation, and the various physical-chemical-biological processes of contaminant containment. Additionally, the review provides case studies of contaminant containment operations under real or simulated field conditions. In summary, contaminant containment measures are essential for preventing further contamination and reducing risks to public health and the environment. While periodic monitoring is necessary, the benefits of contaminant containment make it a valuable remediation option when other methods are not feasible

Response of Cyclopia subternata to drought stress � assessment of leaf composition, proteomics and product quality

Honeybush tea is made from the fynbos plant Cyclopia subternata, which is unique to South Africa. Cultivation takes place in its natural environment, which has a Mediterranean climate with dry summers and wet winters. During the summer, the plant is vulnerable to drought, an abiotic stress factor that is likely to affect its development and yield. This study investigated the effect of drought stress for a short duration on the leaf, as well as the quality of the herbal tea. Protein expression in the leaf was measured to gain insight into possible mechanisms used by the plant to cope with drought stress conditions. Fifteen-month-old C. subternata plants were subjected to three water treatments (control, moderately-stressed (MS), and severelystressed (SS)) for ten days. Leaves were sampled at regular intervals throughout the treatment period to determine their relative water content (RWC). Leaves were also sampled on the 11th day for untargeted and targeted chemical composition and protein expression analyses. The remaining leaves and stems were processed to obtain the herbal tea. Descriptive sensory analysis of the herbal tea was performed to determine whether drought stress affected product quality. RWC was substantially higher (p < 0.05) in the control plants (100%) than in the MS and SS treated plants (83�90% and 47%, respectively). Untargeted analysis revealed that drought stress considerably altered leaf chemical composition. According to targeted analysis, the proline content of SS treated plants increased more than 40-fold when compared to the control, however, the treatments had no effect on the total carbohydrate and major phenolic compound content of the leaves, nor on the sensory quality of the herbal tea. Differences in the expression of 27 proteins, 24 of which were identified using proteomic analysis, were observed. During drought stress, 17 of these proteins increased, whereas seven decreased. Thirteen of the 24 identified proteins produced statistically significant results based on their Byonic scores. The findings laid the foundation for future research into the functions of drought response genes in Cyclopia species, as well as helping with the identification of stress-tolerant honeybush genotypes

Biological Flora of Britain and Ireland: Geranium pratense

1. This account presents information on all aspects of the biology of Geranium pratense L. (Meadow Crane's-Bill). The main topics are presented within the standard framework of the Biological Flora of Britain and Ireland : distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, history and conservation. 2. Geranium pratense is a perennial gynodioecious forb of neutral grassland. In Britain and Ireland, it is particularly abundant on roadside verges, railway embankments, the margins of watercourses and woodland rides. It is generally intolerant of grazing and is absent or scarce in livestock-grazed grassland. Geranium pratense is widespread in England, Wales and Scotland but is scarce in Ireland. It has an extensive native range in Europe and Asia, extending eastwards to Russia, north-western China and Mongolia. It has been widely introduced to new sites within its native range and has been introduced to Canada, the USA and New Zealand. 3. Geranium pratense usually occurs on free-draining soils but also infrequently where drainage is impeded. The soils are often nutrient-rich and weakly acidic to weakly alkaline. The underlying geology is usually non-acidic sedimentary rocks or superficial deposits. 4. Geranium pratense is protandrous and is pollinated by various insects of the orders Hymenoptera, Diptera and Lepidoptera, particularly bumblebees, solitary bees, hoverflies and butterflies. Eleven species of phytophagous insect have been recorded on G. pratense in Britain and Ireland. 5. Geranium pratense has little or no capacity for vegetative spread. Primary seed dispersal is ballistic and seeds may be flung over distances of up to several metres. The species has a transient seed bank, that is germination typically takes place in the winter and spring after seed production, after the physically dormant seeds have become permeable. Seedling establishment is higher in vegetation-free gaps than in undisturbed grassland vegetation. 6. There has been no significant change in its distribution between the late 1950s and 2019, although since 2000, it has expanded its range, mainly via introductions, in northern and western Scotland, west Wales and in Ireland. Alien sites have increased markedly since the 1960s due to introductions from wildflower seed sowing and spread from gardens