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Long-term immobilization of cadmium and lead with biochar in frozen-thawed soils of farmland in China
2022
Liu, Mingxuan | Hou, Renjie | Fu, Qiang | Li, Tianxiao | Zhang, Shoujie | Su, Anshuang
The problem of potentially toxic elements (PTEs) in farmland is a key issue in global pollution prevention and control and has an important impact on environmental safety, human health, and sustainable agricultural development. Based on the climate background of high–latitude cold regions, this study simulated freeze–thaw cycles through indoor tests. Different initial conditions, such as biochar application rates (0%, 1%, 2%) and different initial soil moisture contents (15%, 20%, 25%), were set to explore the morphological changes in cadmium (Cd) and lead (Pb) in soil and the response relationship to the changes in soil physicochemical properties. The results indicate that soil pH decreases during freeze–thaw cycles, and soil alkalinity increases with increasing biochar content. Freeze–thaw cycles caused the total amount of PTEs to have a U–shaped distribution, and the amount of PTEs in the soluble (SOL) and reducible (RED) fraction increased by 0.28–56.19%. Biochar reduced the amount of Cd and Pb migration in the soil, and an increase in soil moisture content reduced the availability of Cd and Pb in the soil. Freezing and thawing damaged the soil structure, and biochar reduced the fractionation of small particle aggregates by enhancing the stability of soil aggregates, thereby reducing the soil's ability to adsorb Cd and Pb. In summary, for farmland soil remediation and pollution control, the application of biochar has a certain ability to optimize soil properties. Considering the distribution of PTEs in the soil and the physicochemical properties of the soil, the application of 1% biochar to soil with a 20% moisture content is optimal for regulating seasonally frozen soil remediation.
显示更多 [+] 显示较少 [-]Soil contamination by microplastics in relation to local agricultural development as revealed by FTIR, ICP-MS and pyrolysis-GC/MS
2022
Chouchene, Khawla | Nacci, Tommaso | Modugno, Francesca | Castelvetro, Valter | Ksibi, Mohamed
Plastic film mulching and use of wastewaters for irrigation have been common agricultural practices for over half a century in Tunisia, especially in arid regions, resulting in the undesired creation of a pathway for microplastics (MPs) to enter farmland soil. In order to assess the extent and characteristics of soil contamination by MPs in the Moknine province, an area of intensive agricultural practices, 16 farmland soil samples were collected and characterized. The total concentration of targeted MPs was 50–880 items/kg; among them, the most common MPs type being polypropylene (PP), mainly occurring as white/transparent fibers with small size (cross section <0.3 mm). SEM images of MPs surfaces revealed multiple features related to environmental exposure and degradation. ATR-FTIR spectroscopy and pyrolysis-GC/MS analyses enabled the accurate identification of MPs separated from the embedding soil micro- and macro-aggregates. Finally, contamination of the polymeric microparticles with a broad range of metals was found by ICP-MS analysis, suggesting that MPs can be vectors for transporting heavy metals in the soil and indicators of soil contamination as a result of mismanagement of industrial wastewaters.
显示更多 [+] 显示较少 [-]Influences of irrigation and fertilization on soil N cycle and losses from wheat–maize cropping system in northern China
2021
Excess of water irrigation and fertilizer consumption by crops has resulted in high soil nitrogen (N) losses and underground water contamination not only in China but worldwide. This study explored the effects of soil N input, soil N output, as well as the effect of different irrigation and N- fertilizer managements on residual N. For this, two consecutive years of winter wheat (Triticum aestivum L.) –summer maize (Zea mays L.) rotation was conducted with: N applied at 0 kg N ha⁻¹ yr⁻¹, 420 kg N ha⁻¹ yr⁻¹ and 600 kg N ha⁻¹ yr⁻¹ under fertigation (DN0, DN420, DN600), and N applied at 0 kg N ha⁻¹ yr⁻¹ and 600 kg N ha⁻¹ yr⁻¹ under flood irrigation (FN0, FN600). The results demonstrated that low irrigation water consumption resulted in a 57.2% lower of irrigation-N input (p < 0.05) in DN600 when compared to FN600, especially in a rainy year like 2015–2016. For N output, no significant difference was found with all N treatments. Soil gaseous N losses were highly correlated with fertilization (p < 0.001) and were reduced by 23.6%–41.7% when fertilizer N was decreased by 30%. Soil N leaching was highly affected by irrigation and a higher reduction was observed under saving irrigation (reduced by 33.9%–57.3%) than under optimized fertilization (reduced by 23.6%–50.7%). The net N surplus was significantly increased with N application rate but was not affected by irrigation treatments. Under the same N level (600 kg N ha⁻¹ yr⁻¹), fertigation increased the Total Nitrogen (TN) stock by 17.5% (0–100 cm) as compared to flood irrigation. These results highlighted the importance to further reduction of soil N losses under optimized fertilization and irrigation combined with N stabilizers or balanced- N fertilization for future agriculture development.
显示更多 [+] 显示较少 [-]Screening ecological risk of pesticides and emerging contaminants under data limited conditions – Case study modeling urban and agricultural watersheds with OrganoFate
2021
Parker, Nicol | Keller, Arturo A.
The increasing number of chemicals used by society requires accessible, easy to implement tools to perform screening-level ecological risk assessments. However, field data to calibrate and validate screening tools is challenging to obtain for many watersheds. Thus, the evaluation must be done under data limited conditions. Here we employ a fate and transport model, OrganoFate, to predict environmental concentrations of contaminants of emerging concern (CECs) as well as a number of pesticides. CECs evaluated include antibacterial compounds sulfamethoxazole and triclocarban and a flame-retardant tris(1,3-dichloro-2-propyl)phosphate (TDCPP). We also evaluated widely used pesticides chlorpyrifos, bifenthrin and esfenvalerate. We predict concentrations of the contaminants in high-risk watersheds which were dominated by either urban or agricultural development and have small aquatic compartments. Screening-level predictions were in good agreement with observed concentrations in surface water and sediment. Maximum predicted concentrations were close to the highest observed concentrations for CECs, only ~0.1 μg/L greater for sulfamethoxazole and triclocarban concentrations, and for TDCPP <5 μg/L higher. ChemFate was also employed to screen possible aquatic health impacts. Results demonstrated possible CEC aquatic health risk for TDCPP and triclocarban (risk quotients of 0.9 and 1.1 respectively). For pesticides, exceedance of effect (EC50) and lethal (LC50) endpoints was predicted for various taxonomic groups which include aquatic invertebrates, fish, amphibians, and benthic organisms.
显示更多 [+] 显示较少 [-]Evaluation of genotoxicity in bat species found on agricultural landscapes of the Cerrado savanna, central Brazil
2022
Habitat loss and fragmentation together represent the most significant threat to the world's biodiversity. In order to guarantee the survival of this diversity, the monitoring of bioindicators can provide important insights into the health of a natural environment. In this context, we used the comet assay and micronucleus test to evaluate the genotoxic susceptibility of 126 bats of eight species captured in soybean and sugarcane plantation areas, together with a control area (conservation unit) in the Cerrado savanna of central Brazil. No significant differences were found between the specimens captured in the sugarcane and control areas in the frequency of micronuclei and DNA damage (comet assay). However, the omnivore Phyllostomus hastatus had a higher frequency of nuclear abnormalities than the frugivore Carollia perspicillata in the sugarcane area. Insectivorous and frugivorous bats presented a higher frequency of genotoxic damage than the nectarivores in the soybean area. In general, DNA damage and micronuclei were significantly more frequent in agricultural environments than in the control area. While agricultural development is an economic necessity in developing countries, the impacts on the natural landscape may result in genotoxic damage to the local fauna, such as bats. Over the medium to long term, then DNA damage may have an increasingly negative impact on the wellbeing of the local species.
显示更多 [+] 显示较少 [-]Spatial distribution, ecological and health risk assessment of organophosphorus pesticides identified in the water of Naseri artificial wetland, Iran
2022
Zarei-Choghan, Mohammad | Jorfi, Sahand | Saki, Amal | Jaafarzadeh, Neamatollah
Agricultural development is inevitable to meet the growing need for food. But along with this development, there are unintended and undesirable consequences for human life and the environment that need, found a solution and corrected. One of the most important adverse consequences of agricultural development is the pollution of surface and groundwater resources, which results from various factors such as soil erosion and improper use of different pesticides. This study aimed to conduct an environmental monitoring program in Naseri wetland to determine the concentrations of organophosphorus pesticides (OPPₛ) in water samples and also to evaluate the potential risks (ecological and health risk assessment) of these pesticides. The salting-out assisted liquid-liquid extraction method was used to extract pesticides. The residual concentrations of OPPₛ evaluated by gas chromatography/mass spectrometry (GC/MS). In this study, the ecological risk of OPPₛ calculated for wetland ecosystem, based on the acute risk quotient (RQᵢ) formula with maximum (RQₘₐₓ), mean (RQₘₑₐₙ), and mixture (RQₘᵢₓ) concentrations of organophosphorus pesticides in the wetland water. Also, to assess the health risk of consuming contaminated fish with organophosphate pesticides, the potential non-carcinogenic and carcinogenic risks were determined by the hazard quotient (Index) (HQ, HI) and incremental lifetime cancer risk (ILCR) indices, respectively. The mean ± SD concentration of OPPₛ (Chlorpyrifos, Malathion, Ethion, Dichlorvos, Trifluralin and Diazinon) in samples of wetland water ranged from 0.14 ± 0.08 to 0.35 ± 0.12 and 0.054 ± 0.06 to 0.2 ± 0.1 (μg/L) in summer and autumn, respectively. The mean ± SD of OPPₛ in fish varied from 0.68 ± 0.86 to 3.94 ± 2.7 (μg/kg). Overall, the concentrations of pesticides in all water and fish samples were below the maximum residue limit (30 μg/kg) during the study period, according to the Environmental Protection Agency (EPA) and the World Health Organization (WHO). The results of acute risk quotient were in summer (RQₘₐₓ = 3.49E-4 to 0.067, RQₘₑₐₙ = 5.8E-5 to 0.029, RQₘᵢₓ = 0.139-0.026, 0.018-3.42E-3) and autumn (RQₘₐₓ = 8E-4 to 0.051, RQₘₑₐₙ = 7.74E-6 to 0.018 RQₘᵢₓ = 0.1–0.013, 6E-3- 1.5E-3). The non-carcinogenic and carcinogenic risk indexes due to fish consumption for adults and children were (HQ = 0.026-4.68E-4, HI = 0.041, ILCR = 1.7E-7) and (HQ = 1.85E-3-1.3E-5, HI = 0.041, ILCR = 5.55E-8), respectively. The risk of OPPₛ was generally low. But cumulative risk (pesticide mixtures), should not be ignored.
显示更多 [+] 显示较少 [-]Land use change in the river basins of the Great Barrier Reef, 1860 to 2019: A foundation for understanding environmental history across the catchment to reef continuum
2021
Lewis, Stephen E. | Bartley, Rebecca | Wilkinson, Scott N. | Bainbridge, Zoe T. | Henderson, Anne E. | James, Cassandra S. | Irvine, Scott A. | Brodie, J. E. (Jon E.)
Land use in the catchments draining to the Great Barrier Reef lagoon has changed considerably since the introduction of livestock grazing, various crops, mining and urban development. Together these changes have resulted in increased pollutant loads and impaired coastal water quality. This study compiled records to produce annual time-series since 1860 of human population, livestock numbers and agricultural areas at the scale of surface drainage river basins, natural resource management regions and the whole Great Barrier Reef catchment area. Cattle and several crops have experienced progressive expansion interspersed by declines associated with droughts and diseases. Land uses which have experienced all time maxima since the year 2000 include cattle numbers and the areas of sugar cane, bananas and cotton. A Burdekin Basin case study shows that sediment loads initially increased with the introduction of livestock and mining, remained elevated with agricultural development, and declined slightly with the Burdekin Falls Dam construction.
显示更多 [+] 显示较少 [-]Does the new-type urbanization construction improve the efficiency of agricultural green water utilization in the Yangtze River Economic Belt?
2021
Ding, Xuhui | Cai, Zhongyao | Fu, Zhu
It is very important to control agricultural water pollution and promote agricultural water saving, for high-quality development of Yangtze River Economic Belt (YREB). The efficiency of agricultural green water utilization (EAGWU) needs financial and technical support from the new-type urbanization, which also change agricultural production mode and resource utilization level. This paper introduces non-point source water pollution into the output, adopts the super efficiency-slack model (SE-SBM) to measure the EAGWU, and uses difference generalized method of moments (DIF-GMM) to examine how new-type urbanization affects EAGWU from its four core characteristics. The results of EAGWU show that the overall efficiency value has been increasing rapidly in the research period, while the eastern provinces performed better and the central provinces performed worse. On the other hand, the overall difference in EAGWU first diverged and then shrunk, while economically developed provinces has been converging all the time. The results of driving factor estimation show that population urbanization has a significantly positive effect on EAGWU, with the rural labor force transfer and agricultural land circulation. Economic urbanization and urban-rural integration have negative effects, with the widening gap of absolute income and the compressed space of agricultural development. The EAGWU lag phase has a positive effect, because of the ratchet or cumulative effect, while equilibrium-urbanization has an insignificant effect. The conclusions will provide preferable recommendations for decision-making of green and water-saving development in agriculture.
显示更多 [+] 显示较少 [-]Knowledge domain and emerging trends of climate-smart agriculture: a bibliometric study
2022
Li, Jun | Xia, Enjun | Wang, Lingling | Yan, Kuan | Zhu, Li | Huang, Jieping
Climate-smart agriculture (CSA) is a new agricultural development pattern to address future food crises. Since CSA was proposed in 2010, it has attracted the attention of scholars from all over the world. It is of great significance to scientifically summarize the overview and emerging trends of CSA research, providing ideas for scholars concerned about CSA to engage in research in this field. Based on bibliometrics and CSA-related literature data in the WOS database, this paper used CiteSpace software to draw knowledge maps to scientifically analyze publications in the field of CSA. Our study found that (1) CSA research is showing a rapid upward trend, focusing on the environmental sciences and agricultural economic management; (2) international organizations such as the FAO, World Bank, and the international agricultural research institute have made significant contributions to CSA research; (3) among the nine clusters in the CSA literature, CSA practice, conservation agriculture, smallholder farmers, and sub-Saharan Africa have been consistently given high attention; (4) CSA research can be divided into three phases, and the research hotspots have transferred from essential elements of CSA to household and carbon emissions. We believe that in future research, more attention should be paid to the trade-off and synergy of the three pillars of CSA, as well as the investment, finance, and evaluation criteria of CSA. Such strengthening is of great significance to the sustainable promotion of CSA.
显示更多 [+] 显示较少 [-]Assessment of agri-environmental situation in selected EU countries: a multi-criteria decision-making approach for sustainable agricultural development
2022
Namiotko, Virginia | Galnaityte, Aiste | Krisciukaitiene, Irena | Balezentis, Tomas
In recent years, humanity has faced with multiple crises, both of economic and environmental nature. Among the key reasons for such turbulences, the deteriorating agri-environmental situation appears as an important facet. This article evaluates agri-environmental situation of selected European Union (EU) countries using the multi-criteria decision making methods (SAW, TOPSIS, and EDAS) to identify the potential strategies for improvement of agricultural activities and environmental situation in general. The set of indicators, compiled from the database, prepared by the European Commission (EC) was used for this research. The empirical results show that the trends in agri-environmental situation of selected EU countries are similar under all the methods used. The best agri-environmental situation both at the beginning and at the end of the research period was in Finland, Ireland, and Sweden. On contrary, the worst situation was identified in the Netherlands, Denmark, and Germany. The only case of decline in the agri-environmental performance is observed for Lithuania, whereas ascension in ranks is observed for Austria and Poland. The results are of particular importance in the period of development of agri-environment and climate schemes for the European Union Common Agricultural Policy post-2020.
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