细化搜索
结果 1-10 的 165
Factors affecting farmers’ use of organic and inorganic fertilizers in South Asia
2021
Aryal, Jeetendra P | Sapkota, Tek Bahadur | Krupnik, Timothy J. | Rahut, Dil B | Jat, Mangi Lal | Stirling, Clare M
Fertilizer, though one of the most essential inputs for increasing agricultural production, is a leading cause of nitrous oxide emissions from agriculture, contributing significantly to global warming. Therefore, understanding factors affecting farmers’ use of fertilizers is crucial to develop strategies to improve its efficient use and to minimize its negative impacts. Using data from 2528 households across the Indo-Gangetic Plains in India, Nepal, and Bangladesh, this study examines the factors affecting farmers’ use of organic and inorganic fertilizers for the two most important cereal crops – rice and wheat. Together, these crops provide the bulk of calories consumed in the region. As nitrogen (N) fertilizer is the major source of global warming and other environmental effects, we also examine the factors contributing to its overuse. We applied multiple regression models to understand the factors influencing the use of inorganic fertilizer, Heckman models to understand the likelihood and intensity of organic fertilizer (manure) use, and a probit model to examine the over-use of N fertilizer. Our results indicate that various socio-economic and geographical factors influence the use of organic and inorganic fertilizers in rice and wheat. Across the study sites, N fertilizer over-use is the highest in Haryana (India) and the lowest in Nepal. Across all locations, farmers reported a decline in manure application, concomitant with a lack of awareness of the principles of appropriate fertilizer management that can limit environmental externalities. Educational programs highlighting measures to improving nutrient-use-efficiency and reducing the negative externalities of N fertilizer over-use are proposed to address these problems.
显示更多 [+] 显示较少 [-]Updated stomatal flux and flux-effect models for wheat for quantifying effects of ozone on grain yield, grain mass and protein yield
2012
Grünhage, Ludger, L. | Pleijel, Hakan, H. | Mills, Gina, G. | Bender, Jürgen, J. | Danielsson, Helena, H. | Lehmann, Yvonne, Y. | Castell, Jean-François, J.-F. | Bethenod, Olivier, O. | Department of Plant Ecology ; Justus-Liebig-Universität Gießen = Justus Liebig University (JLU) | Department of Plant and Environmental Sciences ; University of Gothenburg (GU) | Centre for Ecology and Hydrology [Bangor] (CEH) ; Natural Environment Research Council (NERC) | Institute of Biodiversity ; Johann Heinrich von Thünen-Institute | Environnement et Grandes Cultures (EGC) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech | Swedish Environment Protection Agency; Defra [AQ0810, AQ0816, AQ0601]; LRTAP Convention; NERC; French National Research Agency, ANR
Field measurements and open-top chamber experiments using nine current European winter wheat cultivars provided a data set that was used to revise and improve the parameterisation of a stomatal conductance model for wheat, including a revised value for maximum stomatal conductance and new functions for phenology and soil moisture. For the calculation of stomatal conductance for ozone a diffusivity ratio between O(3) and H(2)O in air of 0.663 was applied, based on a critical review of the literature. By applying the improved parameterisation for stomatal conductance, new flux-effect relationships for grain yield, grain mass and protein yield were developed for use in ozone risk assessments including effects on food security. An example of application of the flux model at the local scale in Germany shows that negative effects of ozone on wheat grain yield were likely each year and on protein yield in most years since the mid 1980s.
显示更多 [+] 显示较少 [-]Updated stomatal flux and flux-effect models for wheat for quantifying effects of ozone on grain yield, grain mass and protein yield
2012
Grünhage, Ludger, L. | Pleijel, Hakan, H. | Mills, Gina, G. | Bender, Jürgen, J. | Danielsson, Helena, H. | Lehmann, Yvonne, Y. | Castell, Jean-François, J.-F. | Bethenod, Olivier, O. | Department of Plant Ecology ; Justus-Liebig-Universität Gießen = Justus Liebig University (JLU) | Department of Plant and Environmental Sciences ; Göteborgs Universitet = University of Gothenburg (GU) | Centre for Ecology and Hydrology [Bangor] (CEH) ; Natural Environment Research Council (NERC) | Institute of Biodiversity ; Johann Heinrich von Thünen-Institut = Thünen Institute | Environnement et Grandes Cultures (EGC) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech | Swedish Environment Protection Agency; Defra [AQ0810, AQ0816, AQ0601]; LRTAP Convention; NERC; French National Research Agency, ANR
Field measurements and open-top chamber experiments using nine current European winter wheat cultivars provided a data set that was used to revise and improve the parameterisation of a stomatal conductance model for wheat, including a revised value for maximum stomatal conductance and new functions for phenology and soil moisture. For the calculation of stomatal conductance for ozone a diffusivity ratio between O(3) and H(2)O in air of 0.663 was applied, based on a critical review of the literature. By applying the improved parameterisation for stomatal conductance, new flux-effect relationships for grain yield, grain mass and protein yield were developed for use in ozone risk assessments including effects on food security. An example of application of the flux model at the local scale in Germany shows that negative effects of ozone on wheat grain yield were likely each year and on protein yield in most years since the mid 1980s.
显示更多 [+] 显示较少 [-]Assessment of elevated CO2 concentrations and heat stress episodes in soybean cultivars growing in heavy metal polluted soils: Crop nutritional quality and food safety
2022
Blanco, Andrés | Högy, Petra | Zikeli, Sabine | Pignata, María L. | Rodriguez, Judith H.
The present study evaluated the interactive effects of global change and heavy metals on the growth and development of three soybean [Glycine max (L.) Merrill] cultivars and the consequences on yield and food safety. Soybean cultivars (Alim 3.14 from Argentina, and ES Mentor and Sigalia, from Germany) were grown until maturity in heavy metals polluted soils from the Rhine Valley, Germany, at two CO₂ concentrations (400 and 550 ppm) and heat stress (HS) episodes (9 days with 10 °C higher than maximum regular temperature) during the critical growth period in controlled environmental chambers. Different morpho-physiological parameters, heavy metal concentration in aerial organs, seed quality parameters, and toxicological index were recorded. The results showed that no morphological differences were observed related to CO₂. Moreover, Alim 3.14 showed the highest yield under control conditions, but it was more sensitive to climatic conditions than the German cultivars, especially to heat stress which strongly reduces the biomass of the fruits. Heavy metals concentration in soil exceeds the legislation limits for agricultural soils for Cd and Pb, with 1.6 and 487 mg kg⁻¹ respectively. In all cultivars, soybeans accumulated Cd in its aerial organs, and it could be translocated to fruits. Cd concentration in seeds ranged between 0.6 and 2.4 mg kg⁻¹, which exceed legislation limits and with toxicological risk to potential Chinese consumers. Pb levels were lower than Cd in seeds (0.03–0.17 mg kg⁻¹), and the accumulation were concentrated in the vegetative organs, with 93% of the Pb incorporated. Moreover, pods accumulated 11 times more Pb than seeds, which suggests that they act as a barrier to the passage of Pb to their offspring. These results evidence that soybean can easily translocate Cd, but not Pb, to reproductive organs. No regular patterns were observed in relation to climatic influence on heavy metal uptake.
显示更多 [+] 显示较少 [-]Nano-enabled agrochemicals/materials: Potential human health impact, risk assessment, management strategies and future prospects
2022
Okeke, Emmanuel Sunday | Ezeorba, Timothy Prince Chidike | Mao, Guanghua | Chen, Yao | Feng, Weiwei | Wu, Xiangyang
Nanotechnology is a rapidly developing technology that will have a significant impact on product development in the next few years. The technology is already being employed in cutting-edge cosmetic and healthcare products. Nanotechnology and nanoparticles have a strong potential for product and process innovation in the food industrial sector. This is already being demonstrated by food product availability made using nanotechnology. Nanotechnologies will have an impact on food security, packaging materials, delivery systems, bioavailability, and new disease detection materials in the food production chain, contributing to the UN Millennium Development Goals targets. Food products using nanoparticles are already gaining traction into the market, with an emphasis on online sales. This means that pre- and post-marketing regulatory frameworks and risk assessments must meet certain standards. There are potential advantages of nanotechnologies for agriculture, consumers and the food industry at large as they are with other new and growing technologies. However, little is understood about the safety implications of applying nanotechnologies to agriculture and incorporating nanoparticles into food. As a result, policymakers and scientists must move quickly, as regulatory systems appear to require change, and scientists should contribute to these adaptations. Their combined efforts should make it easier to reduce health and environmental impacts while also promoting the economic growth of nanotechnologies in the food supply chain. This review highlighted the benefits of a number of nano enabled agrochemicals/materials, the potential health impacts as well as the risk assessment and risk management for nanoparticles in the agriculture and food production chain.
显示更多 [+] 显示较少 [-]The neonicotinoid thiamethoxam impairs male fertility in solitary bees, Osmia cornuta
2021
Strobl, Verena | Albrecht, Matthias | Villamar-Bouza, Laura | Tosi, Simone | Neumann, Peter | Straub, Lars
The ongoing loss of global biodiversity is endangering ecosystem functioning and human food security. While environmental pollutants are well known to reduce fertility, the potential effects of common neonicotinoid insecticides on insect fertility remain poorly understood. Here, we show that field-realistic neonicotinoid exposure can drastically impact male insect fertility. In the laboratory, male and female solitary bees Osmia cornuta were exposed to four concentrations of the neonicotinoid thiamethoxam to measure survival, food consumption, and sperm traits. Despite males being exposed to higher dosages of thiamethoxam, females revealed an overall increased hazard rate for survival; suggesting sex-specific differences in toxicological sensitivity. All tested sublethal concentrations (i.e., 1.5, 4.5 and 10 ng g⁻¹) reduced sperm quantity by 57% and viability by 42% on average, with the lowest tested concentration leading to a reduction in total living sperm by 90%. As the tested sublethal concentrations match estimates of global neonicotinoid pollution, this reveals a plausible mechanism for population declines, thereby reflecting a realistic concern. An immediate reduction in environmental pollutants is required to decelerate the ongoing loss of biodiversity.
显示更多 [+] 显示较少 [-]The impacts of land reclamation on the accumulation of key elements in wetland ecosystems in the Sanjiang Plain, northeast China
2018
Gao, Chuanyu | Zhang, Shaoqing | Liu, Hanxiang | Cong, Jinxin | Li, Yunhui | Wang, Guoping
The Sanjiang Plain, which is located in northeastern China, given the distribution of temperate freshwater wetlands there and this region has considerable significance in ensuring food security in China. Two periods of farmland reclamation that occurred during the last 100 years led to the loss of nearly 80% of the area of the native wetlands, and the development of agriculture has also increased the potential environmental risks to the residual wetlands. To evaluate the effects of farmland reclamation on the accumulation of key elements within the residual wetland ecosystems, six wetland profiles in the Sanjiang Plain are selected in this study. Using age-depth models and the concentrations of key elements, the historical accumulation rates (ARs) of carbon (C), nutrient elements (N and P) and potentially toxic elements (Hg, As, Pb, Cu, and Zn) over the last 150 years are reconstructed. The results show that the ARs of the potentially toxic elements in two of the wetland profiles begin to increase during the first reclamation period (AD 1900–1930). The ARs of both of the key elements clearly increase in all of the wetland profiles during the second reclamation period (AD 1950–1980). After land reclamation had ceased, increases in population and the development of industry became major factors that caused the potential environmental risks to wetlands to continue to increase from AD 1980 to the present. During the last 100 years, reclamation has increased the potential environmental risks and has led to the storage of additional carbon in the residual wetlands of the Sanjiang Plain.
显示更多 [+] 显示较少 [-]‘Agricultural Waste to Treasure’ – Biochar and eggshell to impede soil antibiotics/antibiotic resistant bacteria (genes) from accumulating in Solanum tuberosum L
2018
Jiao, Wentao | Du, Ruijun | Ye, Mao | Sun, Mingming | Feng, Yanfang | Wan, Jinzhong | Zhao, Yuanchao | Zhang, Zhongyun | Huang, Duan | Du, Daolin | Jiang, Xin
Soil contamination with antibiotics and antibiotic resistant bacteria/genes (ARB/ARGs) has becoming an emerging environmental problem. Moreover, the mixed pollutants' transfer and accumulation from soil to tuberous vegetables has posed a great threat against food security and human health. In this work, the application of two absorbing materials (maize biochar and sulfate modified eggshell) was able to reduce the poisonous effect of soil antibiotics on potato root system by stimulate the dissipation of water-soluble antibiotics in soil; and also improve food quality by increasing potato starch, protein, fat, and vitamins. Meanwhile, both amendments could effectively decrease the classes and the accumulative abundance of ARB and ARGs (sulI, sulII, catI, catII, ermA, ermB) in the edible parts of potato. The lowest abundance of ARGs was detected in the biochar application treatment, with the accumulative ARG level of 8.9 × 10² and 7.2 × 10² copies mL⁻¹ in potato peel (sull + catI + ermA) and tuberous root (sulI), respectively. It is the first study to demonstrate the feasibility of biochar and eggshell derived from agricultural wastes as green absorbing materials to reduce soil antibiotic, ARB, and ARGs accumulation risk in tuberous vegetable.
显示更多 [+] 显示较少 [-]Breeding of ozone resistant rice: Relevance, approaches and challenges
2015
Frei, Michael
Tropospheric ozone concentrations have been rising across Asia, and will continue to rise during the 21st century. Ozone affects rice yields through reductions in spikelet number, spikelet fertility, and grain size. Moreover, ozone leads to changes in rice grain and straw quality. Therefore the breeding of ozone tolerant rice varieties is warranted. The mapping of quantitative trait loci (QTL) using bi-parental populations identified several tolerance QTL mitigating symptom formation, grain yield losses, or the degradation of straw quality. A genome-wide association study (GWAS) demonstrated substantial natural genotypic variation in ozone tolerance in rice, and revealed that the genetic architecture of ozone tolerance in rice is dominated by multiple medium and small effect loci. Transgenic approaches targeting tolerance mechanisms such as antioxidant capacity are also discussed. It is concluded that the breeding of ozone tolerant rice can contribute substantially to the global food security, and is feasible using different breeding approaches.
显示更多 [+] 显示较少 [-]Assessing the effects of ambient ozone in China on snap bean genotypes by using ethylenediurea (EDU)
2015
Yuan, Xiangyang | Calatayud, Vicent | Jiang, Lijun | Manning, William J. | Hayes, Felicity | Tian, Yuan | Feng, Zhaozhong
Four genotypes of snap bean (Phaseolus vulgaris L.) were selected to study the effects of ambient ozone concentration at a cropland area around Beijing by using 450 ppm of ethylenediurea (EDU) as a chemical protectant. During the growing season, the 8h (9:00–17:00) average ozone concentration was very high, approximately 71.3 ppb, and AOT40 was 29.0 ppm.h. All genotypes showed foliar injury, but ozone-sensitive genotypes exhibited much more injury than ozone-tolerant ones. Compared with control, EDU significantly alleviated foliar injury, increased photosynthesis rate and chlorophyll a fluorescence, Vcmax and Jmax, and seed and pod weights in ozone-sensitive genotypes but not in ozone-tolerant genotypes. EDU did not significantly affect antioxidant contents in any of the genotypes. Therefore, EDU effectively protected sensitive genotypes from ambient ozone damage, while protection on ozone-tolerant genotypes was limited. EDU can be regarded as a useful tool in risk assessment of ambient ozone on food security.
显示更多 [+] 显示较少 [-]