Search Results (389)

Greenhouses have positively impacted plant production by allowing the cultivation of different crops per year. However, the accumulation of agricultural plastics, potentially contaminated with agrochemicals, raises environmental concerns. This work evaluates the combined effect of Bordeaux mixture and low-density polyethylene (LDPE) microplastics (<5 mm) on the growth of lettuce (Lactuca sativa L.) and soil microbial communities. Different levels of Bordeaux mixture (0, 100 and 500 mg kg⁻¹), equivalent to Cu(II) concentrations (0, 17 and 83 mg kg⁻¹), LDPE microplastics (0, 1% and 5%) and their combination were selected. After 28 days of growth, biometric and photosynthetic parameters, Cu uptake, and soil microbial responses were evaluated. Plant germination and growth were not significantly affected by the combination of Cu and plastics. However, individual Cu treatments influenced root and shoot length and biomass. Chlorophyll and carotenoid concentrations increased with Cu addition, although the differences were not statistically significant. Phospholipid fatty acid (PLFA) analysis revealed a reduction in microbial biomass at the highest Cu dose, whereas LDPE alone showed limited effects and may reduce Cu bioavailability. These results suggest that even at the highest concentration added, Cu can act as a plant nutrient, while the combination of Cu–plastics showed varying effects on plant growth and soil microbial communities. Full article

Efficient plastic waste end-of-life management is a serious worldwide environmental issue motivated by growing waste production and negative effects of wrongful disposal. This study presents a comparative overview of plastic waste management regimes within the European Union (EU), the United States of America (USA), and Romania, ranked with circular economy goals. By using the United States Environmental Protection Agency (US EPA) Waste Reduction Model (WARM), version 16, the study provides a quantified score to greenhouse gas (GHG) emissions within three large options of management: recycling, energy recovery through combustion, and landfilling. The model setup utilizes region-specific information on legislation, base technology, and recycling efficiency. The outcomes show that recycling always entails net GHG emissions reductions, i.e., −4.49 kg CO_2e/capita/year for EU plastic waste and −20 kg CO_2e/capita/year for USA plastic waste. Combustion and landfilling have positive net emissions from 1.76 to 14.24 kg CO_2e/capita/year. Economic indicators derived from the model also show significant variation: salaries for PET management amounted to USD 2.87 billion in the EU and USD 377 million in the USA, and tax collection was USD 506 million and USD 2.01 billion, respectively. The conclusions highlight the wider environmental and socioeconomic benefits of recycling and reinforce its status as a cornerstone of circular-economy sustainable plastic waste management and a strategic element of national development agendas, with special reference to Romania’s national agenda. Full article

The practice in agriculture of spreading polyethylene (PE) film over the soil surface as mulch is a common, global practice that aids in conserving water, increasing crop yields, suppressing weed growth, and decreasing growing time. However, these films are typically only used for a single growing season, and thus, their use and non-biodegradability come with some serious environmental consequences due to their persistence in the soil and potential for microplastic pollution, particularly when retrieval and disposal options are poor. On the microscale, particles < 5 mm from degraded films have been observed to disrupt soil structure, impede water and nutrient cycling, and affect soil organisms and plant health. On the macroscale, there are obvious and serious environmental consequences associated with the burning of plastic film and its leakage from poorly managed landfills. To maintain the crop productivity afforded by mulching with PE film while avoiding the environmental downsides, the development and use of biodegradable polymer technologies is being explored. Here, the efficacy of a newly developed, water-dispersible, sprayable, and biodegradable polyester–urethane–urea (PEUU)-based polymer was compared with two commercial PE mulches, non-degradable polyethylene (NPE) and OPE (ox-degradable polyethylene), in a greenhouse tomato growth trial. Water savings and the effects on plant growth and soil characteristics were studied. It was found that PEUU provided similar water savings to the commercial PE-based mulches, up to 30–35%, while showing no deleterious effects on plant growth. The results should be taken as preliminary indications that the sprayable, biodegradable PEUU shows promise as a replacement for PE mulch, with further studies under outside field conditions warranted to assess its cost effectiveness in improving crop yields and, importantly, its longer-term impacts on soil and terrestrial fauna. Full article

Global climate change has intensified the challenges of low-temperature, low-light, and high-humidity microclimates in North China’s greenhouses during winter, exposing the limitations of traditional controlled-environment agriculture (CEA) facilities. This study monitored air temperature, relative humidity, and light intensity in three greenhouse types—an externally insulated plastic greenhouse, soft-shell solar greenhouse, and brick-walled solar greenhouse—across three overwintering periods (pre-, mid-, post-) using high-precision sensors (monitoring period is from 1 October 2024 to 31 March 2025). A Comprehensive Evaluation Index (CEI) based on the entropy method was developed, integrating seven indicators (daily average temperature, temperature range, hours below 5 °C, average humidity, hours above 80% humidity, average light intensity, and light utilization efficiency) to systematically evaluate greenhouse microclimate regulation performance. Results showed that the brick-walled solar greenhouse exhibited superior thermal insulation, with nearly zero hours below 5 °C during mid-overwintering, while the soft-shell solar greenhouse achieved the highest light utilization efficiency (75.1–79.6%). The externally insulated plastic greenhouse exhibited the highest relative humidity (>80% for 13–19 h/day) but a poor thermal insulation performance. The CEI ranked the brick-walled solar greenhouse (0.86) and the soft-shell solar greenhouse (0.84) significantly higher than the externally insulated plastic greenhouse (0.39), with the relative humidity significantly negatively correlated with light indicators (P < 0.05), and the temperature and light indicators strongly correlated with the CEI (P < 0.01). Structural design and material innovation are critical for climate adaptation. Brick-walled and soft-shell solar greenhouses balance thermal and light performance, while the externally insulated plastic greenhouse faces structural limitations. The findings provide a scientific basis for greenhouse optimization and regional layout planning. Full article

The rapid expansion of plastic waste trade has intensified environmental pressures, accelerating ecosystem degradation and climate change. We examine the long-term impacts of plastic waste imports and domestic waste production on ecological footprints and greenhouse gas emissions across 20 countries representing 70% of global plastic waste trade and 45% of world GDP. Under the Environmental Kuznets Curve (EKC) framework, we explore nonlinear interactions among economic growth, urbanization, and sustainability goals. Using a panel simultaneous equations approach, we apply Pedroni, Kao, and Westerlund cointegration tests and Fully Modified and Dynamic OLS estimators to address endogeneity and heterogeneity. Robustness checks include alternative environmental indicators and the Dumitrescu–Hurlin panel causality test. Results demonstrate a stable long-run equilibrium: plastic waste imports substantially increase ecological footprints and emissions, while progress on sustainable development goals mitigates some damage. The negative GDP squared coefficient supports the EKC hypothesis, indicating that environmental impacts rise initially with growth but decline once income exceeds a threshold. These findings highlight the need for stronger international regulations, enhanced waste management infrastructures, and circular economy strategies. Focused investment in sustainable technologies and global cooperation is essential to lower environmental costs of plastic waste trade. Full article

Agricultural production in Northwest China is widely constrained by residual plastic film pollution, excessive greenhouse gas emissions, and low productivity. Integrating biodegradable film with controlled-release nitrogen fertilizer offers a promising approach to optimize crop management, enhance yield, and improve environmental outcomes. In this study, three planting patterns (conventional flat planting, FP; ridge mulching with biodegradable film, BM; and ridge mulching with conventional plastic film, PM), two nitrogen fertilizer types (urea, U, and controlled-release nitrogen fertilizer, C), and four nitrogen application rates (0, 80, 160, and 240 kg·hm⁻²) were applied to systematically investigate their effects on alfalfa yield and N₂O emissions from grasslands. The results showed that BM and PM increased alfalfa yield by 23.49% and 18.65%, respectively, compared to FP, while C increased yield by 8.46% compared to urea. The highest yield (24.84 t·hm⁻²) was recorded under the BMC2 treatment, which was 97.11% higher than that of FPN0. N₂O emission flux and cumulative emissions increased with nitrogen application rate. Compared with U, C reduced cumulative N₂O emissions and greenhouse gas emission intensity (GHGI) by 23.89% and 25.84%, respectively. Compared to PM, BM reduced cumulative N₂O emissions and GHGI by 11.58% and 20.15%, respectively. Principal component analysis indicated that the combination of ridge mulching with biodegradable film and 160 kg·hm⁻² of C was optimal for simultaneously increasing alfalfa yield and reducing N₂O emissions, making it a suitable planting–fertilization strategy for the Yellow River irrigation district in Gansu and similar ecological regions. Full article

Plastic is extensively used in nursery and greenhouse operations. Concerns are growing about the potential release of plastic byproducts, such as microplastics and per- and poly-fluoroalkyl substances (PFAS), into water resources. The purpose of this study was to (1) compare perceptions of plastic use and water quality impacts between scientists researching water contaminants and nursery/greenhouse growers, (2) identify barriers to growers reducing plastic use, and (3) explore preferred communication channels for scientists to inform growers about emerging research. An online survey was administered to collect data from scientists in a USDA-funded multi-state Hatch project (N = 20) and nursery/greenhouse growers (N = 66) across the United States. The findings indicated both groups were unsure of the impacts of plastic use. While most respondents perceived surface water pollution as a critical issue, neither scientists nor growers strongly agreed on-farm plastic use poses a significant threat. Both groups recognized the importance of regular water testing, but few believed mandatory changes to plastic use should be enacted without further evidence. Growers cited limited equipment, financial constraints, and uncertain availability of viable plastic alternatives as key barriers. Despite these barriers, growers were willing to learn more, primarily through online resources, short courses, and workshops. The findings underscore the need for targeted research that quantifies plastic byproducts in nursery/greenhouse water and identifies cost-effective alternatives. Timely dissemination of scientific findings using trusted sources will be critical to bridge knowledge gaps and support adoption of best practices to safeguard water quality in surface and groundwater. Full article

The main objective of this work was to evaluate new variants of passive heating systems used for horticultural crop cycles planted in the cold period in low-cost greenhouses on the Mediterranean Spanish coast (a mild-winter area). The double low cover (DLC) is variant of the conventional fixed plastic screen that reduces the air volume and increases the airtightness around crops. Three identical DLCs were installed inside a typical greenhouse, and the microclimate measured in the three DLCs was similar. The DLCs reduced the solar radiation transmissivity coefficient by around 0.05 but increased the mean daily substrate and air temperatures (up to 1.6 and 3.6 °C, respectively). They also modified the air humidity, although this can be modulated by opening the vertical sheets located on the greenhouse aisles (DLC vents). The black plastic mulch forming an air chamber around the substrate bags (BMC), a new mulch variant used in substrate-grown crops, increased the substrate temperature with respect to the conventional black mulch covering the entire ground surface. The combination of BMC plus DLC increased the mean daily substrate temperature by up to 2.9 °C, especially at night. Low tunnels covered with transparent film and with a spun-bonded fabric sheet were also compared, and both materials were efficient heating systems regarding substrate and air temperatures. Low tunnels combined with the DLC substantially increased air humidity, but this can be partially offset by opening the DLC vents. The combination of low tunnels and DLC does not seem recommendable for greenhouse crops planted in winter, since both systems reduce solar radiation transmissivity. Full article

The large-span insulated plastic greenhouse is a highly promising horticultural facility. The design parameters and configuration of structural components significantly impact their safety and load-bearing performance. However, current research in this field remains insufficient. In this study, the deformation, stress distribution, and stability of large-span insulated plastic greenhouses with different structural configurations were investigated using the finite element method. Subsequently, the ultimate bearing capacity of large-span insulated plastic greenhouses with varying ridge heights was examined. The research indicated that the greenhouse with a plane truss and double-layer tie rod exhibited the smallest deformation and stress in its members, as well as the highest ultimate load-bearing capacity. The analysis revealed that the installation of double-layer tie rods not only enhanced the collaborative effect of arch frames within the structural calculation unit but also reduced displacement along the Z direction, effectively mitigated the $\mathrm{P}-∆$ effect, reduced out-of-plane bending stress, and improved the ultimate load-bearing capacity. Ridge height affected the load-bearing capacity of the greenhouse structure. However, a higher ridge height did not necessarily result in a stronger ultimate load-bearing capacity. The greenhouse structure with a ridge height of 5 m demonstrated the maximum ultimate load-bearing capacity, capable of bearing 1.98 times the initial load. This study provides theoretical support for the configuration of structural components of large-span insulated plastic greenhouses and offers a scientific basis for the optimal design of ridge height. Full article

Accurate extraction of plastic greenhouses from high-resolution remote sensing imagery is essential for agricultural resource management and facility-based crop monitoring. However, the dense spatial distribution, irregular morphology, and complex background interference of greenhouses often limit the effectiveness of conventional segmentation methods. This study proposes a deep learning framework that integrates a multi-scale Transformer-based decoder with a Swin-UNet architecture to improve feature representation and extraction accuracy. To enhance geometric consistency, a post-processing strategy is introduced, combining connected component analysis and morphological operations to suppress noise and refine boundary shapes. Using GF-2 satellite imagery over Weifang City, China, the model achieved a recall of 92.44%, precision of 91.47%, intersection-over-union of 85.13%, and F1-score of 91.95%. In addition to instance-level extraction, spatial distribution and statistical analysis were performed across administrative divisions, revealing regional disparities in protected agriculture development. The proposed approach offers a practical solution for greenhouse mapping and supports broader applications in land use monitoring, agricultural policy enforcement, and resource inventory. Full article

The chemical industry faces major challenges worldwide. Since 1950, production has increased 50-fold and is projected to continue growing, particularly in Asia. It is one of the most energy- and resource-intensive industries, contributing significantly to greenhouse gas emissions and the depletion of finite resources. This development exceeds planetary boundaries and calls for a sustainable transformation of the industry. The key transformation areas are as follows: (1) Non-Fossil Energy Supply: The industry must transition away from fossil fuels. Renewable electricity can replace natural gas, while green hydrogen can be used for high-temperature processes. (2) Circularity: Chemical production remains largely linear, with most products ending up as waste. Sustainable product design and improved recycling processes are crucial. (3) Non-Fossil Feedstock: To achieve greenhouse gas neutrality, oil, gas, and coal must be replaced by recycling plastics, renewable biomaterials, or CO₂-based processes. (4) Sustainable Chemical Production: Energy and resource savings can be achieved through advancements like catalysis, biotechnology, microreactors, and new separation techniques. (5) Sustainable Chemical Products: Chemicals should be designed to be “Safe and Sustainable by Design” (SSbD), meaning they should not have hazardous properties unless essential to their function. (6) Sufficiency: Beyond efficiency and circularity, reducing overall material flows is essential to stay within planetary boundaries. This shift requires political, economic, and societal efforts. Achieving greenhouse gas neutrality in Europe by 2050 demands swift and decisive action from industry, governments, and society. The speed of transformation is currently too slow to reach this goal. Science can drive innovation, but international agreements are necessary to establish a binding framework for action. Full article

Agrivoltaic greenhouses in southern Spain offer a sustainable way to manage excessive irradiance levels by generating renewable energy. This study presents a shading experiment on tomato cultivation in a raspa-y-amagado greenhouse in Almeria, southern Spain, during the 2023–2024 growing season. Photovoltaic modules were mimicked by opaque plastic sheets that were arranged in a checkerboard pattern on the roof of the greenhouse. Two shading zones (30% and 50% roof cover ratio) were compared against an unshaded control zone. Microclimate, plant physiology, yield and quality were monitored during the study. The results show that shading influenced the microclimate, which directly impacted crop yield. The 30% and 50% shading zones resulted in 15% and 26% crop yield reductions, respectively. A preliminary, theoretical analysis of potential revenues of the photovoltaic yield showed that reductions in crop yield can be overcompensated by the energy generated by the PV system. For the summer crop cycle, a higher PV production and lower crop yield reductions can be expected. The economic advantage demonstrates the potential of agrivoltaic greenhouses in southern Spain. Full article

This study investigates how different types of microplastics (MPs)—fibers, glitter, plastic bags, and plastic bottles—influence heavy metal uptake in lettuce (Lactuca sativa L.), a commonly consumed leafy vegetable. A controlled eight-week pot experiment was conducted in a greenhouse using contaminated loamy sand soil (polluted with Cd, Pb, Cu, and other metals) collected from a smelter-impacted area. Microplastics were added at a concentration of 70–80 mg/kg, and lettuce seedlings were grown under phytotron conditions (22 ± 2 °C, 60 ± 5% RH, 16 h light/8 h dark) without fertilizers or external contaminants. Plant roots and shoots were harvested, and heavy metals were analyzed via MP-AES and ICP-MS. The results showed that MPs altered heavy metal mobility, bioavailability, and plant uptake. Copper accumulation in leaves decreased substantially across MP treatments, from 80.84 mg/kg in the control to 26.35 mg/kg (glitter), whereas lead and cadmium concentrations increased significantly in roots under fiber and glitter exposure (Pb increased from 12.13 mg/kg to 33.57 mg/kg and Cd from 1.70 mg/kg to 2.05 mg/kg in fiber treatment). Cobalt accumulation in leaves increased under the plastic bag treatment, indicating MP-specific metal interactions. Root growth was also affected, with fibers promoting elongation and plastic bottles restricting it. Sequential extraction revealed that MPs modified metal partitioning in soil, with Pb and Ni more strongly retained in stable fractions under some treatments. Observed trends in soil pH and organic matter content were associated with changes in metal mobility, highlighting the potential role of soil properties in mediating microplastic–metal interactions. These findings highlight the role of MPs as mediators of heavy metal transport in crops and underscore the need for clear regulatory guidelines that limit microplastic contamination in agricultural soils and promote routine monitoring to safeguard food safety and crop health. Full article

Despite the emphasis on consumption and production patterns in the Sustainable Development Goals (SDGs), plastic pollution remains inadequately addressed. This research contributes to the limited literature on sustainable consumption and disposal of plastic in developing contexts and demonstrates how universities can effectively integrate sustainability competencies into a subject-specific curriculum. This study examined how teacher training programs can address plastic pollution through curriculum innovation and experiential challenge-based learning. Focusing on technology student teachers (TSTs) at a South African institution, the research explored their experiences with community-based problem-solving activities related to plastic consumption and disposal. The polymer module was restructured to combine theoretical knowledge with practical sustainability actions, engaging students in real-world environmental challenges. Data were generated via focus group interview, reflective journal, and photovoice. Working in teams across four communities, TSTs conducted plastic audits in households, shared findings with community members, and collaboratively developed sustainable solutions. This approach bridged the gap between academic learning and environmental action, addressing the critical global plastic crisis that contributes to fossil fuel depletion, ecosystem damage, and greenhouse gas emissions. The findings highlight the potential of teacher education to cultivate environmentally conscious educators who can inspire sustainable thinking and action across educational settings. The practical implications of this research extend beyond the classroom, offering a replicable model for teacher education programs to empower future educators as change agents who can facilitate sustainable community action through knowledge co-creation and context-specific environmental problem-solving. Full article

The western honeybee, Apis mellifera, is used worldwide as a pollinator of crops such as strawberries; however, it is an introduced species in Japan. The mason bee, Osmia orientalis Benoist (Hymenoptera: Megachilidae), is native to Japan, where it nests in empty snail shells and has potential as a crop pollinator. We conducted three experiments to collect information on the nesting habits and potential agricultural use of this species as a pollinator of greenhouse-grown strawberries. Our first experiment investigated the bees’ nesting preferences in the field by placing the empty shells of four snail species, Euhadra amaliae, Satsuma japonica, Sinotaia quadrata histrica, and Helix lucorum, in six different environments. The nesting rate was significantly higher in medium-sized, empty E. amaliae shells. Regarding the surrounding environment, O. orientalis preferred tall and short grasslands to bare ground and forest interiors. Our second experiment investigated per-visit strawberry flower pollination efficiency. The results indicated that the efficiency of O. orientalis was equal to or greater than that of A. mellifera. In our third experiment, as a replacement for empty snail shells, which are scarce natural sources, four types of plastic artificial shells were created and placed inside a greenhouse together with E. amaliae shells. The nesting rates in three types of artificial shells were nearly identical to those in E. amaliae shells, implying that these artificial shells may be effective nesting materials. Although many questions remain before practical application, our results indicate the potential for using O. orientalis as a pollinator of greenhouse-grown strawberries. Full article