scholarly journals Oxadiazon Dissipation in Water and Topsoil in Flooded and Dry-Seeded Rice Fields

Agronomy ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 557 ◽  
Author(s):  
Marco Milan ◽  
Aldo Ferrero ◽  
Silvia Fogliatto ◽  
Serenella Piano ◽  
Michéle Negre ◽  
...  
Keyword(s):  
Residence Time ◽  
Half Life ◽  
Rice Fields ◽  
Water Bodies ◽  
Paddy Fields ◽  
North West ◽  
Paddy Water ◽  
Growing Seasons ◽  
Over Time

The aim of the present study was to assess the behavior of oxadiazon in topsoil and waters of paddy fields cultivated according to the two rice seeding systems: conventional water seeding (CON) and dry seeding (DRY). The study was carried out from 2012 to 2013 in Vercelli, north-west of Italy, the most important rice growing area of Europe. Variations in oxadiazon concentrations were studied over time in topsoil, paddy water, inlet water and outlet water. Over the two years, the estimated oxadiazon topsoil half-life was 3.27 days, without significant differences between systems and years. Oxadiazon dissipation in the paddy water was rapid during the first week, but less pronounced late in the season. Residues of oxadiazon were frequently detected in inlet waters. Transfer of oxadiazon residues in outlet waters occurred over all the growing seasons, with important peaks in the first weeks after the treatment. A possible way to reduce the transfer of oxadiazon to water bodies could be increasing the residence time of the herbicide in the paddy fields during the first 7–10 days after spraying, avoiding the release of water from them.

scholarly journals Zooplankton community responses to the mixture of imazethapyr with imazapic and bispyribac-sodium herbicides under rice paddy water conditions

2014 ◽  
Vol 44 (8) ◽  
pp. 1392-1397 ◽  
Author(s):  
Geovane Boschmann Reimche ◽  
Sérgio Luiz de Oliveira Machado ◽  
Renato Zanella ◽  
Michele Câmara de Vicari ◽  
Fernando Piccinini ◽  
...  
Keyword(s):  
Half Life ◽  
Zooplankton Community ◽  
Rice Paddy ◽  
Paddy Fields ◽  
Community Responses ◽  
Paddy Water ◽  
Adult Copepod ◽  
Water Conditions ◽  
Rice Paddy Fields

The aim of this study was to assess the effect of concentrations of imazethapyr, imazapic, and bispyribac-sodium herbicides on zooplankton community (Cladocer, Copepod and Rotifer) in rice paddy fields. The decrease of half-life dissipation (DT50) of the herbicides under study in water was: imazethapyr, imazapic, and bispyribac-sodium with an average of 3.75, 3.73 and 1.91 days, respectively. The mixture of imazethapyr with imazapic caused change in the analyzed zooplankton, with an increase in the densities of Cladocer and adult Copepod groups, while bispyribac-sodium caused a reduction of density in Copepod group, both adults and nauplii, in the initial samples. Among the groups, Rotifer was slightly sensitive to the herbicides.

scholarly journals Pesticide Use Practices and Effects on the Wetland Biodiversity of Ndop, North West Region of Cameroon

2021 ◽  
pp. 105-116
Author(s):  
Nkwatoh Therese Ncheuveu ◽  
Patricia Bi Asanga Fai ◽  
Martin Ngankam Tchamba ◽  
Francis Ngealekeloeh
Keyword(s):  
Population Decline ◽  
Clarias Gariepinus ◽  
Water Bodies ◽  
Paddy Fields ◽  
Pesticide Use ◽  
North West ◽  
Vegetable Farmers ◽  
West Region ◽  
Wetland Biodiversity ◽  
Significant Difference

Aims: The aim of this study was to evaluate farmer’s pesticide use practices and their effects in the wetland of Ndop. Study Design: A cross sectional study was carried out from January to August 2019 in Ndop, North West Region of Cameroon. Methodology: Questionnaires were administered separately to 382 rice and 100 vegetable farmers, and descriptive statistics was used in analyzing the results. Specifically, the Chi-squared statistic was used to determine the nature of the relationship between the variables. Results: The results showed that most of the crop fields (95.6%) lack a buffer zone since most farms were adjacent to water bodies (0 ≥farm ≥1 m). Farmers (100%) washed and rinsed knapsack sprayers in nearby water bodies. A majority of the farmers (71.3%) burnt or threw empty pesticide containers in open fields, water bodies, or nearby bushes. Both rice farmers (83.5%) and vegetable farmers (100%) reported that pesticides kill non-target organisms (fish, frogs, toad, snakes, birds, etc.) resulting into a drastic population decline in the wetland. A majority of the farmers (85.2%) no longer do fishing in the paddy fields because of the frequent fish decline caused by pesticide usage. Clarias gariepinus constituted 56% of the fish species harvested from the paddy fields and a drastic population decline was observed by the farmers. The average fish catch per month was low (12.22 kg ± 7.47 SD) relative to the past when pesticides were not used during cultivation.  There was a significant difference between training and environmental awareness of pesticides (X2 = 28.98, p = 0.001). Conclusion: These results indicate an urgent need for a post-pesticide registration management strategy to ensure a sustainable management and conservation of the wetland resources of Ndop.

scholarly journals Off-site movement of quinclorac from rice fields

2021 ◽  
Author(s):  
Francesco Vidotto ◽  
Silvia Fogliatto ◽  
Lorenzo Carmagnola ◽  
Fernando De Palo ◽  
Marco Milan
Keyword(s):  
Management Practices ◽  
Water Discharge ◽  
Field Studies ◽  
Paddy Fields ◽  
Irrigation District ◽  
Public And Private ◽  
Paddy Water ◽  
Holding Period ◽  
Growing Seasons ◽  
Public And Private Stakeholders

Highlights - Quinclorac persistence in paddy water is affected by its residues in entering waters. - Entering waters often contain quinclorac residues. - A water holding period of at least 10 days may limit the offsite movement of quinclorac residues from paddy fields. Abstract The off-site movement of quinclorac from rice paddies was studied in a district and field study during the 2014 and 2015 growing seasons. Quinclorac residues were monitored on in-field surface waters, and out-field water entering and leaving an irrigation district. The behavior of quinclorac residues in paddy water pointed out that the movement of herbicides from interconnected paddies is not negligible. This phenomenon was particularly evident in the days following the re-flooding of paddies after spraying. The water entering the uphill paddy fields have partially flushed quinclorac residues in the downhill paddy fields. Both the district and the field studies, showed the continuous presence of quinclorac residues in inlet waters. Even because of the continuous uploading of residues from inlet waters, traces of quinclorac in paddy water were detected up to 70 DAT. The presence of quinclorac in inlet water could be related to phenomena of drainage and drift during herbicide application in the paddies located upstream. The analysis carried out on waters leaving the district showed the presence of quinclorac residues in all the outlet floodgates, particularly from the end of May and late August. The results of this study suggest that appropriate management practices adopted at field scale may be required to lower the water contamination at irrigation district level. Considering that the highest losses of quinclorac occurred during the first 10-15 days after its application, to prevent these losses could be helpful avoiding water discharge from the treated fields for at least this period of time. In addition, a deep effort must be laid upon education and training of farmers on these environmental thematic throughout specific initiatives organized by public and private stakeholders.

scholarly journals Diagnostic yield of gastrointestinal endoscopy in North West Region Cameroon and trends in diagnosis over time

2018 ◽  
Vol 29 ◽  
Author(s):  
Jacob Kamdem ◽  
Dennis Palmer ◽  
Charles Barrier ◽  
Richard Bardin ◽  
James Allen Brown ◽  
...  
Keyword(s):  
Gastrointestinal Endoscopy ◽  
Diagnostic Yield ◽  
North West ◽  
West Region ◽  
Over Time

scholarly journals Personal fund of hydropower engineer S. V. Grigoriev of the Museum-archive of the BCH KSC RAS

2021 ◽  
Vol 12 (4-2021) ◽  
pp. 28-36
Author(s):  
O. V. Shabalina ◽  
◽  
K. S. Kazakova ◽  
Keyword(s):  
Scientific Study ◽  
Water Bodies ◽  
The Arctic ◽  
Biographical Information ◽  
North West ◽  
The North ◽  
European North ◽  
Potential Sources ◽  
History Of

The article presents materials from the personal fund of the largest hydropower engineer of the North-West of the USSR S. V. Grigoriev, belonging to the Museum-Archive of History of Studying and Exploration of the European North of the Barents Centre of Humanities of the KSC RAS. The personal documents of the scientist and the practitioner are sources of biographical information given in the article and potential sources for research in the field of the history of the scientific study of water bodies, rivers and the development of hydropower in the Arctic.

scholarly journals Assessment of the groundwater quantitative status in the Aosta Plain (North-West Italy): applicability of the national guidelines defined by ISPRA

2020 ◽  
Author(s):  
Gennaro A. Stefania ◽  
Michele Bigoni ◽  
Chiara Zanotti ◽  
Marco Rotiroti ◽  
Fulvio Simonetto ◽  
...  
Keyword(s):  
Monitoring Network ◽  
Water Bodies ◽  
National Guidelines ◽  
Groundwater Levels ◽  
North West ◽  
Future Assessment ◽  
Surface Water Bodies ◽  
Nw Italy ◽  
The Eu ◽  
Critical Aspects

The EU Water Framework Directive requires Member States to assess the quantitative and qualitative status of groundwater bodies and to achieve a good status by 2027. The present study was developed in order to assess the groundwater quantitative status in the Aosta Plain (NW Italy), following the methodology proposed through a guideline defined by the Italian Institute for Environmental Protection and Research (ISPRA), with the aim of supporting local authorities in their periodic assessment of water bodies status. In the study area, during the period 2000-2017, groundwater levels were measured in 213 wells and piezometers. Performing the four tests required by the abovementioned guideline, the quantitative status was assessed on the basis of multi-year groundwater level variations, water balance and the interconnections of groundwater with surface water bodies and groundwaterdependent ecosystems. A good status was assessed for the study area, although some critical aspects emerged from the application of the guideline methodology: the data collected by the monitoring network are not sufficiently robust in terms of sample size, spatial distribution, temporal interval and frequency to fulfill the requirements of the guideline methodology. Therefore, some recommendations to improve the data quality and better address the future assessment of groundwater quantitative status were given.

Software for Statistical Meta-analysis

2013 ◽  
Author(s):  
Christopher H. Schmid ◽  
Gavin B. Stewart ◽  
Hannah R. Rothstein ◽  
Marc J. Lajeunesse ◽  
Jessica Gurevitch
Keyword(s):  
Half Life ◽  
Meta Analysis ◽  
Research Synthesis ◽  
General Purpose ◽  
User Needs ◽  
Specific Information ◽  
Graphical Display ◽  
Web Searches ◽  
General Purpose Software ◽  
Over Time

To conduct a meta-analysis, a researcher will need software to perform all but the simplest calculations. Three types of software can be used, depending on user needs: a spreadsheet, a general purpose statistical package, and a program developed expressly to carry out meta-analysis. This chapter first reviews the stand-alone programs, then discusses the general purpose software, and finally briefly reviews two programs that can extract the data underlying a graphical display. Readers need to keep in mind that software features, cost, and availability all change fairly rapidly over time; while some of the specific information provided may soon be out of date, the general issues and principles discussed in choosing software for meta-analysis will have a longer half-life. Web searches, the Methods sections of recent research syntheses, and professional meetings where research synthesis results and methods are presented, are good resources for keeping up with both software availability and developments in methodology.

scholarly journals Ecological Niche Models Reveal Climate Change Effect on Biogeographical Regions: The Iberian Peninsula as a Case Study

Climate ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 42 ◽  
Author(s):  
Diana Sousa-Guedes ◽  
Salvador Arenas-Castro ◽  
Neftalí Sillero
Keyword(s):  
Iberian Peninsula ◽  
Environmental Conditions ◽  
Atlantic Coast ◽  
Group Method ◽  
Ecological Niche Models ◽  
North West ◽  
Pair Group ◽  
Climate Change Effect ◽  
Biogeographical Regions ◽  
Over Time

How species are distributed on Earth depends largely on climate factors. Whenever these environmental conditions change, species tend to shift their distributions to reach more favourable conditions. Distinct sets of species similarly distributed (i.e., chorotypes) occur in biogeographical regions with homogeneous environmental conditions. Here, we analysed whether biogeographical regions are unstable over time (from the past to the future). We modelled the realised niche of amphibians and reptiles in the Iberian Peninsula in the present, and several past and future climate scenarios. Then, we used Jaccard’s index and the unweighted pair group method (UPGMA) to define the biogeographical regions. Our results suggest that the biogeographical regions of Iberian amphibians and reptiles changed greatly over time, due to the climatic changes between periods. Biogeographical regions composed of species with Atlantic affinities changed particularly, overall gaining suitable areas in past colder periods and losing suitable areas in warmer periods. The areas of refugia for amphibians over time corresponded to the most humid regions (north-west of the peninsula), while the most important areas for reptiles occur in the south and on the Atlantic coast. The identification of biogeographical patterns considering past climate changes is essential to better apply conservation measures.

Propaganda and Protest in Autocracies

2020 ◽  
pp. 002200272097509
Author(s):  
Erin Baggott Carter ◽  
Brett L. Carter
Keyword(s):  
Standard Deviation ◽  
Half Life ◽  
Popular Protest ◽  
Original Dataset ◽  
Initial Effect ◽  
Temporal Persistence ◽  
Over Time

Does propaganda reduce the rate of popular protest in autocracies? To answer this question, we draw on an original dataset of state-run newspapers from thirty countries, encompassing six languages and over four million articles. We find that propaganda diminishes the rate of protest, and that its effects persist over time. By increasing the level of pro-regime propaganda by one standard deviation, autocrats have reduced the odds of protest the following day by 15%. The half-life of this effect is between five and ten days, and very little of the initial effect persists after one month. This temporal persistence is remarkably consistent with campaign advertisements in democracies.

scholarly journals Ichthyo-faunal diversity of Morang district, Nepal

Our Nature ◽  
2017 ◽  
Vol 15 (1-2) ◽  
pp. 55-67
Author(s):  
Bharat Raj Subba ◽  
Nelson Pokharel ◽  
Manish Raj Pandey
Keyword(s):  
Fish Species ◽  
Water Bodies ◽  
Paddy Fields ◽  
Stream Fishes ◽  
Faunal Diversity ◽  
One Year ◽  
Schizothorax Plagiostomus

The present paper attempts to report a total of 118 fish species spread over 11 orders, 26 families and 64 genera inhabited indifferent water bodies viz, rivers, reservoirs, streams, ponds, lakes, canals, ditches, paddy fields of Morang district, collected during a one-year survey. The order Cypriniformes is the richest one among 11 orders that comprises 59 species followed by Siluriformes having 31 and Perciformes with 19 representatives, respectively. Orders Anguilliformes, Osteoglossiformes, Beloniformes, Cyprinodontiformes, Synbranchiformes and Tetraodontiformes have only one representative. Olyra longicaudata is the new report from Morang district and the second report from Nepal. Besides this, other hill-stream fishes viz., Pseudecheneis sulcatus, Schizothorax plagiostomus, Schistura savona and Neolissochilus hexagonolepis recorded during the survey, also have not been previously reported from this district.

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