خيارات البحث
النتائج 1 - 10 من 13
Effects of chlorimuron ethyl on terrestrial and wetland plants: Levels of, and time to recovery following sublethal exposure
2013
Carpenter, David | Boutin, Céline | Allison, Jane E.
Current pesticide registration guidelines call for short-term testing of plants; long-term effects on vegetative parts and reproduction remain untested. The aims of our study were to determine level of recovery and recovery times for plants exposed to the sulfonylurea herbicide chlorimuron ethyl using data collected from single species, dose–response greenhouse experiments. The nine terrestrial and eight wetland species tested showed variable levels of recovery and recovery timeframes. Many species (six terrestrial and five wetland) were vegetatively stunted at sublethal doses and were reproductively impaired. Full recovery did not occur at all doses and maximum recovery times varied from 3 to 15 weeks in this controlled environment. In a complex community, affected species may be displaced by tolerant species, through interspecific competition, before they fully recover. It is plausible that individual populations could be diminished or eliminated through reduced seedbank inputs (annuals and perennials) and asexual reproduction (perennials).
اظهر المزيد [+] اقل [-]A Bayesian network for analyzing biological acute and long-term impacts of an oil spill in the Gulf of Finland
2011
Lecklin, Tiina | Ryömä, Riitta | Kuikka, Sakari
Knowledge of oil-induced impacts from the literature and experts were used to develop a Bayesian network to evaluate the biological consequences of an oil accident in the low-saline Gulf of Finland (GOF). Analysis was carried out for selected groups of organisms. Subnetworks were divided into subgroups according to a predicted response to oil exposure. Two scenario analyses are presented: the most probable and the worst-case accident. The impact of the most probable accident in the GOF is rather small. In most of the groups studied oil-induced long-term effects are evaluated to be minor at least from the perspective of the whole GOF. After the worst-case accident negative effects are more likely. The model predicts that the most vulnerable groups are auks and ducks. Amphipods, gulls and to a lesser extend littoral fishes and seals may show delayed recovery after an accident. Also annual plant species may be susceptible to oil-induced disturbances.
اظهر المزيد [+] اقل [-]Screening effects of metsulfuron-methyl to collembolans and earthworms: the role of adjuvant addition on ecotoxicity
2018
de Santo, Fernanda Benedet | Ramos, Guilherme Alves | Ricardo Filho, Altair Maçaneiro | Marchioro, Cesar Augusto | Niemeyer, Júlia Carina
Metsulfuron-methyl is a common active ingredient recommended for use in pre- and post-emergence control of annual grasses and broadleaf weeds in crops, usually applied with mineral oil as adjuvant to enhance its efficiency. Despite the increasing use of this herbicide, there are no information on its ecotoxicity effects to soil fauna. Avoidance and lethality tests were performed with earthworms and collembolans using tropical artificial soil contaminated with formulated products Ally® (600 g L⁻¹ metsulfuron-methyl) and Assist® (756 g L⁻¹ mineral oil) as adjuvant. Lethality test with earthworms showed no difference when tested with or without adjuvant. When Ally® was tested alone, it caused avoidance behavior only at high concentrations (5000 and 10,000 times field predicted dose). However, Assist® addition changed the response of soil invertebrates increasing the avoidance even at field predicted doses. The toxicity of the adjuvant was confirmed in tests exposing collembolans and earthworms to Assist® alone resulting in avoidance behavior. The results clearly show that the addition of mineral oil enhanced the ecotoxicity of metsulfuron-methyl. This study provides an important contribution to the knowledge on the toxicity of metsulfuron-methyl and indicates that adjuvants should be considered in risk assessment of pesticides, considering that under field conditions, these products are applied together.
اظهر المزيد [+] اقل [-]The impact of Rumex vesicarius seed water extracts on mice fertility
2022
Alhimaidi, Ahmad Rashed | Ammari, Aiman Abdullah | Okla, Mohammad Khair | Algadi, Muath Qasem | Amran, Ramzi Ahmed | Alhusayni, Hissah Ibrahim | Alhimaidi, Mohammed Ahmad
Rumex vesicarius (RV) is an edible wild annual plant, and it is reported that it contains a good source of minerals, protein, and ascorbic acid. Several studies have indicated the anti-liver damage, anticancer, antimicrobial, and antioxidant properties of the RV plant. There are currently no reports regarding the effect of RV on fertility. Therefore, this study focuses on the impact of RV water seed extracts on mice fertility. RV plants were collected, and water seed extracts were prepared; 50 mg/kg body weight (BW) of this was then injected into the mice (male and female) using an oral feeding tube 5 days before mating (group I) or during caging of the females with the males for 1 week to detect their fertility rate. In the different female groups, no significant difference between their BW and their newborn’s BW in the treated and control groups was found. Female fertility, pregnancy, and offspring rates showed some variation within each female group and between the different female groups. In comparing the fertility and offspring rate between the different groups, there was a significant difference (P < 0.05) between groups I and III females and between groups I and IV females, while the other groups showed no significant differences. In contrast, the other groups showed no significant differences. Regarding the impact of the water seed extract on males, the BW was approximately the same in control and treated males.
اظهر المزيد [+] اقل [-]Carbon Storage Potential of a Waterlogged Agroforestry System of Tripura, India
2021
Sarkar, P. K. (Pradip Kumar) | Sarkar, Pranati | Kumar, Amit | Pala, Nazir A. | Kumar, Munesh
The present study reports the potential of carbon (C) storage in traditional agroforestry systems (i.e., a set of age-old agroforestry systems) under waterlogged environmental conditions from north-eastern India. An experiment was conducted in a farmer’s field and further used CO₂FIX model, allometric equations, and destructive sampling methods to know the potential of C sequestration. In this study area, agroforestry system is dominated by woody perennials like Areca catechu, Cocos nucifera, Mangifera indica, Artocarpus heterophyllus, Melocanna baccifera, and Colocasia esculenta as annual crop component. Need-based management of the drainage system has been built-up by making broad/narrow bunds for maintaining water levels at different stages of plant growth. The total annual carbon storage potential of this traditional agroforestry system was estimated as 103.760±8.630 t ha⁻¹year⁻¹. The highest annual carbon storage potential (97.900±8.090 t ha⁻¹year⁻¹) was recorded in annual crop components (i.e., Colocasia) followed by trees and its underlaid soil (4.250±0.340 t ha⁻¹year⁻¹) and lowest for bamboos (1.610± 0. 200 t ha⁻¹ year⁻¹). However, the estimated carbon stored, annually, was 24.992±1.502 t ha⁻¹ year⁻¹ in which Colocasia share maximum contribution (19.600±1.080 t ha⁻¹ year⁻¹) followed by trees + soil (3.798±0.229 t ha⁻¹ year⁻¹) and the minimum contribution from bamboos (1.594±0.193 t ha⁻¹ year⁻¹). Moreover, total carbon loss from harvesting of this system was 78.768±7.128 t ha⁻¹ year⁻¹. The study, therefore, recommends this agroforestry system for other waterlogged ecosystems at regional and/or global scale under a warm per-humid climate for both livelihood opportunities and environmental sustainability.
اظهر المزيد [+] اقل [-]Developing the collection of statistical food waste data on the primary production of fruit and vegetables
2021
Joensuu, Katri | Hartikainen, Hanna | Karppinen, Sirpa | Jaakkonen, Anna-Kaisa | Kuoppa-aho, Mika
In order to meet global goals of reducing food waste, feasible monitoring methods to verify the impact of reduction measures are needed. In this study, a method was developed for gathering food waste data related to the primary production of fruit and vegetables using a questionnaire for farmers. A data collection form was planned and tested for this purpose. Data was collected on the volumes of different uses of yields and the reasons why part of the yield does not end up in food use. The crop species that were included in this pilot study were food potatoes, carrots, white cabbage, and strawberries. In primary production, the share of food use of the total yield was highest for potatoes (96%) and lowest for carrots (72%). In the case of strawberries and white cabbage, 86% and 90% were used as food, respectively. In the future, it is recommended that this kind of survey be added to annual crop production surveys that cover agricultural and horticultural enterprises in Finland. To improve the response rate and decrease the reporting load of farmers, it is important that the questionnaire is designed to be as easy as possible to answer.
اظهر المزيد [+] اقل [-]Winter Rye Cover Crop Impacts on Runoff Water Quality in a Northern New York (USA) Tile-Drained Maize Agroecosystem
2020
Griffith, Keegan E. | Young, Eric O. | Klaiber, Laura B. | Kramer, Stephen R.
Nonpoint source phosphorus (P) and nitrogen (N) pollution from agriculture is a global concern. Planting a cover crop after harvesting annual crops such as maize may help mitigate nutrient transport risk to surface and groundwater. Few studies have focused on the impact of a winter rye cover crop on both surface runoff (SR) and tile drainage (TD) water quality. Here, we measured N and P losses in SR and TD from maize plots grown with and without a winter rye cover crop. Four plots (46 × 23 m) in northern New York, USA, equipped with automated SR and TD flow monitoring were planted with winter rye (Secale cereal) in 2016 and 2017 after maize silage harvest. Plots were managed as typical silage fields for dairy farms in the region and received fertilizer and manure applications. Dissolved reactive P (DRP), total P (TP), nitrate-N, total N (TN), and total suspended solids (TSS) loads were monitored from 4/7/16 to 6/29/17. Cumulative SR (volumetric depth equivalent) was 1.8-fold lower for rye compared to control plots. Although runoff and loading were variable, cumulative TSS, TP, and DRP losses were approximately 3-fold lower for rye plots compared to control. Cumulative TN and nitrate-N loads for TD were similar; however, cumulative TN loss for SR was lower for rye plots. Surface runoff was the main pathway of P loss (> 90% of DRP and TP loss) with > 90% of cumulative P exported from 2017 snowmelt events. Results suggest winter rye mitigated N and P transport risk in SR compared to the common practice of leaving maize silage fields bare after harvest.
اظهر المزيد [+] اقل [-]Assessment of Photodegradation of Herbicide Prometryn in Soil
2017
Jiang, Chen | Li, Xuejing | Wang, YaRu | Ma, Liya | Wang, YaKun | Lu, Yichen | Yang, Hong
Prometryn has been used in crop (e.g., corn and sorghum) field to prevent growth of annual grasses and broadleaf weeds for many years. As a moderately persistent herbicide in soil, prometryn may exert detrimental effects on environmental safety and crop production. The present study assessed the photodegradation of prometryn residues in soil by exploring a variety of factors such as soil moisture, temperature, and light exposure that potentially affect prometryn photodegradation. The dissipation rate of prometryn during a 14-day period of study was more than 90% under 15 (low pressure), 100, and 300 W (medium pressure) UV light exposure. The half-life of prometryn decay under UV light (53.5–116.4 h) was far less than that under xenon light (1131.6 h) and dark (3138.7 h) conditions. When the soil moisture (clay loam) was 60% of the field moisture capacity, it was most effective for prometryn photodegradation. The prometryn photodegradation on soil with 60% moisture level was increased with temperature and prometryn concentrations. The theoretical optimization scheme for eliminating prometryn in soil was recommended. The degraded products of prometryn under UV light and darkness were characterized using ultra high-performance liquid chromatography coupled to a linear ion trap-orbitrap hybrid mass spectrometer (UPLC-LTQ-orbitrap-MS/MS) and showed that prometryn decay in soil was through hydroxylation, dealkylation, and dethiomethylation pathways.
اظهر المزيد [+] اقل [-]Enhancement of nitrogen and phosphorus removal from eutrophic water by economic plant annual ryegrass (Lolium multiflorum) with ion implantation
2014
Li, Miao | Sheng, Guo-ping | Wu, Yue-jin | Yu, Zeng-liang | Bañuelos, Gary S. | Yu, Han-qing
Severe eutrophication of surface water has been a major problem of increasing environmental concern worldwide. In the present study, economic plant annual ryegrass (Lolium multiflorum) was grown in floating mats as an economic plant-based treatment system to evaluate its potential after ion implantation for removing nutrients in simulated eutrophic water. The specific weight growth rate of L. multiflorum with ion implantation was significantly greater than that of the control, and the peroxidase, nitrate reductase, and acid phosphatase activities of the irradiated L. multiflorum were found to be greater than those plants without ion implantation. Higher total nitrogen (TN) and total phosphorus (TP) removal efficiencies were obtained for the L. multiflorum irradiated with 25 keV 5.2 × 10¹⁶ N⁺ions/cm²and 30 keV 4.16 × 10¹⁶ N⁺ions/cm², respectively (p < 0.05). Furthermore, the nitrogen and phosphorus contents in the plant biomass with ion implantation were also greater than those in the control and were positively correlated with TN and TP supplied. L. multiflorum itself was directly responsible for 39–49 and 47–58 % of the overall N and P removal in the experiment, respectively. The research results suggested that ion implantation could become a promising approach for increasing phytoremediation efficiency of nutrients from eutrophic water by L. multiflorum.
اظهر المزيد [+] اقل [-]Nutrient retention in plant biomass and sediments from the salt marsh in Hangzhou Bay estuary, China
2013
Shao, Xuexin | Wu, Ming | Gu, Binhe | Chen, Yinxu | Liang, Xinqiang
Nutrient load into the ocean can be retained during the process of plant uptake and sedimentation in marshes along the bay zone. Seasonal variations of biomass and nutrient concentration in three dominated plant assemblages and associated sediments were monitored in this study area to determine effects of salt marsh on nutrient retention. Results showed that plant aboveground biomass displayed a unimodal curve with nutrient concentration generally decreased from spring to winter. Belowground biomass was relatively low during the rapid growth period with nutrient concentration tending to decrease and then increase during this period. Plant total nitrogen (TN) pools are higher than total phosphorus (TP) pools, and both pools showed significant seasonal variations. Water purification coefficients (WPC) of nutrients by plant assimilation were 34.4/17.3, 19.3/24.0, and 5.14/6.04 t/(m(2) year) (TN/TP) for Phragmites australis, Spartina alterniflora, and Scirpus mariqueter, respectively. Overall, these results suggest that higher annual plant biomass and nutrient assimilation contribute to greater nutrient retention capacity and accumulation in sediments, thereby enabling reduced eutrophication in transitional waters.
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