scholarly journals The Influence of Tillage on Dispersal of Tilletia indica Teliospores from a Concentrated Point Source

Plant Disease ◽  
2008 ◽  
Vol 92 (3) ◽  
pp. 351-356 ◽  
Author(s):  
T. W. Allen ◽  
F. Workneh ◽  
K. C. Steddom ◽  
G. L. Peterson ◽  
C. M. Rush
Keyword(s):  
Spatial Distribution ◽  
Point Source ◽  
Soil Sample ◽  
Soil Samples ◽  
Tilletia Indica ◽  
Total Distance ◽  
Parallel Lines ◽  
Centrifugation Technique ◽  
The Impact ◽  
Soil Area

A study was conducted to determine the impact of tillage on dispersal of Tilletia indica teliospores from a concentrated point source in Arizona. The infested source was created using a 300-ml teliospore suspension, containing approximately 9.0 × 104 teliospores/ml, sprayed onto a 1-by-3-m soil area. Approximately 400 g of soil was collected before tillage treatments, representing the teliospore baseline, and after each of five disk passes, to an approximate depth of 20 cm, through the infestation source (n = 597). Soil samples were collected along three parallel lines extending from the infested area at increments of 1, 3, or 10 m to a total distance of 10, 30, and 50 m, respectively. Teliospores were recovered from soil samples by a combined size-selective sieving sucrose-centrifugation technique. Immediately following teliospore infestation, an average of 3.6 × 103 teliospores per 25 g of soil sample were recovered from the infestation area. Two different trends in recoverable teliospores occurred at 0- to 10-m sampling distances following five plow passes: either a decrease in the number of teliospores recovered, represented at points 0, 1, and 2 m, or an increase in recoverable teliospores found at points 3 to 10 m. The study was repeated twice for a total of three experiments, and teliospores were recovered to a maximum distance of 24 m. However, the numbers recovered from distances beyond 10 m were sporadic. Based on data from this research, we conclude that teliospores are not distributed in large quantities to great distances by tillage and, therefore, tillage cannot account for the spatial distribution of teliospores in many infested wheat fields.

Evaluation of Nanotechniques and Conventional Techniques for the Removal of Dioxins

2018 ◽  
Vol 9 (1) ◽  
pp. 79-84
Author(s):  
Vaishali V. Shahare ◽  
Rajni Grover ◽  
Suman Meena
Keyword(s):  
Soil Sample ◽  
Human Health ◽  
Surface Area ◽  
Contaminated Soil ◽  
Conventional Treatment ◽  
Volume Ratio ◽  
Soil Samples ◽  
Dioxins And Furans ◽  
Palladized Iron ◽  
The Impact

Background: The persistent dioxins/furans has caused a worldwide concern as they influence the human health. Recent research indicates that nonmaterial may prove effective in the degradation of Dioxins/furans. The nanomaterials are very reactive owing to their large surface area to volume ratio and large number of reactive sites. However, nanotechnology applications face both the challenges and the opportunities to influence the area of environmental protection. Objective: i) To study the impact of oil mediated UV-irradiations on the removal of 2,3,7,8-TCDD, 2,3,7,8-TCDF, OCDD and OCDF in simulated soil samples. ii) To compare the conventional treatment methods with the modern available nanotechniques for the removal of selected Dioxins/furans from soil samples. Methods: The present work has investigated an opportunity of the degradation of tetra and octachlorinated dioxins and furans by using oil mediated UV radiations with subsequent extraction of respective dioxins/furans from soils. The results have been compared with the available nanotechniques. Results: The dioxin congeners in the simulated soil sample showed decrease in concentration with the increase in the exposure time and intensity of UV radiations. The dechlorination of PCDD/Fs using palladized iron has been found to be effective. Conclusion: Both the conventional methods and nanotechnology have a dramatic impact on the removal of Dioxins/furans in contaminated soil. However, the nanotechniques are comparatively costlier and despite the relatively high rates of PCDDs dechlorination by Pd/nFe, small fraction of the dioxins are recalcitrant to degradation over considerable exposure times.

Spatial Distribution and Contribution Segregation of Hg and Cd in the Soils in the Chemical Industry Park and its Surrounding Areas

2012 ◽  
Vol 610-613 ◽  
pp. 3797-3802
Author(s):  
Chun Feng Lu ◽  
Sheng Lu Zhou ◽  
Shao Hua Wu
Keyword(s):  
Spatial Distribution ◽  
Chemical Industry ◽  
Wind Direction ◽  
Surface Soil ◽  
Soil Samples ◽  
Contribution Rate ◽  
The North ◽  
Spatial Distribution Characteristics ◽  
Surrounding Areas ◽  
The Impact

This paper determined Hg and Cd contents through collecting the surface soil samples in Nanjing Liuhe Chemical Industry Park and its surrounding areas, analyzed the spatial distribution characteristics of Hg and Cd in the study area by means of ordinary Kriging, and carried out quantitative analysis for the impact of chemical industry park on the accumulation of soil heavy metals through introducing contribution rate. The results show that the chemical industry park is one of the important causes of the accumulation of Hg and Cd in the surrounding soils. In space, the closer the site is to the industrial park, the higher the accumulative content is. Wind direction has a significant effect on the diffusion of Hg, affected most greatly on the northwest, which is located downwind, with a contribution rate of 85.47%, while wind direction has no significant effect on the diffusion of Cd, affected most greatly on the north, with a contribution rate of 29.37%.

scholarly journals Impact of Forest Combustion on Soil Contamination by PAHs Using QuEChERS and GC-MS/MSTQD

2019 ◽  
pp. 1-13
Author(s):  
Al Fahd, Marzoq Hadi. ◽  
Al-Sewailem, Mohamed S. ◽  
EL-Saeid, Mohamed Hamza
Keyword(s):  
Saudi Arabia ◽  
Soil Contamination ◽  
Soil Sample ◽  
Limit Of Detection ◽  
Soil Samples ◽  
Control Surface ◽  
Gas Chromatography Mass Spectrometry ◽  
Limit Of Quantification ◽  
Subsurface Soil ◽  
The Impact

The present study was conducted in one of the most dense forest area of Asir region located in the southwest of Saudi Arabia to study the Impact of Forest Combustion on surface and subsurface soil contamination by Poly Aromatic Hydrocarbons (PAHs). The major toxic effects of PAHs including cancers, immunity suppression, loss of fertility, mutagenic and cardiovascular diseases. The extraction and analytical methods, have been developed and validated for quantification of trace levels of 17 PAHs namely, Naphthalene, Acenaphthylene, Acenaphthene, Fluorene, Phenanthrene, Anthracene, Fluoranthene, Pyrene, Retene, Benzo [b+j] fluoranthene, Benzo (a)pyrene, Benzo [k] fluoranthene, 3-methylchol-anthrene, Dibenz [a,h] acridine, Indeno [1,2,3-cd]pyrene, Dibenz [a,h] anthracene and Benzo [ghi] perylene. Surface and subsurface soil samples were collected from Alsaqa and Murir post-fire forests in Asir Province, Saudi Arabia, and extracted by Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) and analyzed by Gas Chromatography-Mass Spectrometry Triple Quadrupole (GC-MS/MSTQD). The experimental results of 17 compounds of PAHs were highly satisfactory linearity, recovery and precision, especially with the tested soil samples. Recovery % ranged from 96.48±2.19 to 105.61±3.21%., the limit of detection (LOD) ranged from 3.71 to 6.77 µg kg-1. Meanwhile the limit of quantification (LOQ) for the analyzed PAHs were in the range of 10.47 to 16.42 µgkg-1. This method featured good sensitivity, lower quantification limits and the precision of the analyzed 17 PAHs.  The calibration curves were linear over wide concentration ranges with correlation coefficients (r2) 0.7478 to 0.9822 for 17 PAHs analyzed by GC-MS/MSTQD. The concentrations of the investigated PAHs in Alsaqa forest surface (S) and subsurface (SS) soils ranged from F24.81±4.29 to 57.28±3.56 and 24.10±2.31to 55.47±4.15 mg kg-1dry weight respectively. Meanwhile, the PAHs concertation in Murir surface and subsurface soils ranged from 12.48±2.37 to 28.83±3.35 and 12.83±1.37 to 25.59±4.31 mg kg-1 dry weight respectively. Retene compound was detected in Alsaqa, and Murir forest investigated surface, and subsurface soil sample ranged from 57.28, 55.47, and 28.83, 25.59 mg/kg-1(ppm) respectively. Meanwhile, Retene was not detected (ND) in the control surface and subsurface soil sample. The detected PAHs by applying the modified QuEChERS and GC-MS/MSTQD method were applied successfully for the extraction and determination of the 17 PAHs in burned forest soil samples.

KEBERADAAN BAKTERI PELARUT FOSFAT DAN AKTIVITAS ENZIM FOSFATASE TANAH DAERAH PERAKARAN TANAMAN OBAT DARI KEBUN RAYA CIBODAS

2018 ◽  
Vol 6 (3) ◽  
Author(s):  
Suliasih Suliasih
Keyword(s):  
Alkaline Phosphatase ◽  
Soil Sample ◽  
Rhizosphere Soil ◽  
Botanical Garden ◽  
Soil Enzyme ◽  
Soil Samples ◽  
Phosphate Solubilizing Bacteria ◽  
Bacillus Sp ◽  
Phosphate Solubilizing ◽  
Serratia Rubidaea

A study was undertaken to investigate to occurance of phosphate solubilizing bacteria from rhizosphere soil samples of medicine plants in Cibodas Botanical Garden. 13 soil samples of medicine plants are collected randomly The result shows that 71 isolates of phosphate solubilizing bacteria were isolated, and 10 species of these organism was identified as Azotobacter sp, Bacillus sp, Chromobacterium sp, C.violaceum, Citrobacter sp. , Enterobacter sp., E. liquefaciens. Nitrosomonas sp., Serratia rubidaea, Sphaerotillus natans. Azotobacter sp. And Bacillus sp. Are found in all of soil tested. Conversely, Serratia rubidaea is only in the sample from rhizosphere of Plantago mayor The activity of acid alkaline phosphatase in soil tested ranged from 0.78 – 60,18 ugp nitrophenole/g/h, with the higest values being recorded in soil sample from rhizosphere of “Lavender”.Keywords : phosphate solubilizing bacteria, soil enzyme phosphatase

Assessment of Irrigation Quality of Disposal Water of Ashuganj-Polash Agro-Irrigation Project, Brahmanbaria Bangladesh

2017 ◽  
Vol 4 (04) ◽  
Author(s):  
ABDUR RAZZAK ◽  
PARSA SANJANA ◽  
BELAL HOSSAIN ◽  
DEBJIT ROY ◽  
BIDHAN CHANDRA NATH
Keyword(s):  
Soil Sample ◽  
Water Samples ◽  
Crop Production ◽  
Soil Samples ◽  
Chemistry Laboratory ◽  
Total Hardness ◽  
Sodium Absorption ◽  
Irrigation Project ◽  
Crop Field ◽  
Initial Soil

The study was conducted at Ashuganj-Polash agro-irrigation project (APAIP), Brahmanbaria,aim to determine the chemical properties of power plant disposal water and to assess its suitability for irrigation. Initial soil samples (before irrigating crop field) and final soil samples (after crop harvesting) were collected. During irrigation ten water samples (six from crop field and four from irrigation canals) were collected for analysis. All soil samples were analyzed in Humboldt soil testing laboratory and water samples in bio-chemistry laboratory of Bangladesh Agricultural University and compared to FAO irrigation standard. Results show thatthe sodium absorption ratio (SAR) (0.53 to 0.88), residual sodium bi-carbonate (0.8 to 1.3meq L-1), Kelly’s ratio (0.31 to 0.6) and total hardness (85 to 150) found in normal range and largely suitable for irrigation. Soluble sodium percentage values found in satisfactory (20.26 to 41.1) level and magnesium absorption (57.1 to 76.4) found unsuitable for irrigation. Statistically similar value of pH, EC, total nitrogen, organic carbon, calcium, magnesium and phosphorus in initial and final soil sample were observed. But potassium and sulfur value reduced in final soil sample from initial soil. The water samples fall within the permissible limit and found suitable for crop production

Modelling Agricultural Controls for Flooding and Soil Erosion

2018 ◽  
pp. 776-796
Author(s):  
Roger Moussa ◽  
Bruno Cheviron
Keyword(s):  
Spatial Distribution ◽  
Model Structure ◽  
Land Uses ◽  
Research Challenges ◽  
Water And Sediment ◽  
Flow Processes ◽  
Cultivation Practices ◽  
Modelling Strategies ◽  
The Impact ◽  
Significant Factors

Floods are the highest-impact natural disasters. In agricultural basins, anthropogenic features are significant factors in controlling flood and erosion. A hydrological-hydraulic-erosion diagnosis is necessary in order to choose the most relevant action zones and to make recommendations for alternative land uses and cultivation practices in order to control and reduce floods and erosion. This chapter first aims to provide an overview of the flow processes represented in the various possible choices of model structure and refinement. It then focuses on the impact of the spatial distribution and temporal variation of hydrological soil properties in farmed basins, representing their effects on the modelled water and sediment flows. Research challenges and leads are then tackled, trying to identify the conditions in which sufficient adequacy exists between site data and modelling strategies.

scholarly journals Measuring spatial allocative efficiency in basketball

2020 ◽  
Vol 16 (4) ◽  
pp. 271-289
Author(s):  
Nathan Sandholtz ◽  
Jacob Mortensen ◽  
Luke Bornn
Keyword(s):  
Spatial Distribution ◽  
Hierarchical Model ◽  
Opportunity Cost ◽  
Allocative Efficiency ◽  
Bayesian Hierarchical Model ◽  
National Basketball Association ◽  
Spatial Context ◽  
Bayesian Hierarchical ◽  
The Impact

AbstractEvery shot in basketball has an opportunity cost; one player’s shot eliminates all potential opportunities from their teammates for that play. For this reason, player-shot efficiency should ultimately be considered relative to the lineup. This aspect of efficiency—the optimal way to allocate shots within a lineup—is the focus of our paper. Allocative efficiency should be considered in a spatial context since the distribution of shot attempts within a lineup is highly dependent on court location. We propose a new metric for spatial allocative efficiency by comparing a player’s field goal percentage (FG%) to their field goal attempt (FGA) rate in context of both their four teammates on the court and the spatial distribution of their shots. Leveraging publicly available data provided by the National Basketball Association (NBA), we estimate player FG% at every location in the offensive half court using a Bayesian hierarchical model. Then, by ordering a lineup’s estimated FG%s and pairing these rankings with the lineup’s empirical FGA rate rankings, we detect areas where the lineup exhibits inefficient shot allocation. Lastly, we analyze the impact that sub-optimal shot allocation has on a team’s overall offensive potential, demonstrating that inefficient shot allocation correlates with reduced scoring.

A Pandemic of Violence? The Impact of COVID-19 on Conflict

2020 ◽  
Vol 26 (3) ◽  
Author(s):  
Sara M.T. Polo
Keyword(s):  
Spatial Distribution ◽  
Real Time ◽  
Case Studies ◽  
Armed Conflict ◽  
Event Data ◽  
Social Unrest ◽  
Johns Hopkins University ◽  
The World ◽  
Political Advantage ◽  
The Impact

AbstractThis article examines the impact and repercussions of the COVID-19 pandemic on patterns of armed conflict around the world. It argues that there are two main ways in which the pandemic is likely to fuel, rather than mitigate, conflict and engender further violence in conflict-prone countries: (1) the exacerbating effect of COVID-19 on the underlying root causes of conflict and (2) the exploitation of the crisis by governments and non-state actors who have used the coronavirus to gain political advantage and territorial control. The article uses data collected in real-time by the Armed Conflict Location & Event Data Project (ACLED) and the Johns Hopkins University to illustrate the unfolding and spatial distribution of conflict events before and during the pandemic and combine this with three brief case studies of Afghanistan, Nigeria, and Libya. Descriptive evidence shows how levels of violence have remained unabated or even escalated during the first five months of the pandemic and how COVID-19-related social unrest has spread beyond conflict-affected countries.

scholarly journals Spatial distribution patterns of soil total phosphorus influenced by climatic factors in China’s forest ecosystems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jie Zhu ◽  
Anchi Wu ◽  
Guoyi Zhou
Keyword(s):  
Spatial Distribution ◽  
Forest Ecosystems ◽  
Climatic Factors ◽  
Critical Role ◽  
Effect Of Temperature ◽  
P Concentration ◽  
Single Effect ◽  
The Impact ◽  
P Distribution ◽  
Total P

AbstractPhosphorus (P) is an important element in terrestrial ecosystems and plays a critical role in soil quality and ecosystem productivity. Soil total P distributions have undergone large spatial changes as a result of centuries of climate change. It is necessary to study the characteristics of the horizontal and vertical distributions of soil total P and its influencing factors. In particular, the influence of climatic factors on the spatial distribution of soil total P in China’s forest ecosystems remain relatively unknown. Here, we conducted an intensive field investigation in different forest ecosystems in China to assess the effect of climatic factors on soil total P concentration and distribution. The results showed that soil total P concentration significantly decreased with increasing soil depth. The spatial distribution of soil total P increased with increasing latitude and elevation gradient but decreased with increasing longitude gradient. Random forest models and linear regression analyses showed that the explanation rate of bioclimatic factors and their relationship with soil total P concentration gradually decreased with increasing soil depths. Variance partitioning analysis demonstrated that the most important factor affecting soil total P distribution was the combined effect of temperature and precipitation factor, and the single effect of temperature factors had a higher explanation rate compare with the single effect of precipitation factors. This work provides a new farmework for the geographic distribution pattern of soil total P and the impact of climate variability on P distribution in forest ecosystems.

scholarly journals Spatial Dependence Evaluation of Agricultural Technical Efficiency—Based on the Stochastic Frontier and Spatial Econometric Model

2021 ◽  
Vol 13 (5) ◽  
pp. 2708
Author(s):  
Ziqi Yin ◽  
Jianzhai Wu
Keyword(s):  
Spatial Distribution ◽  
Technical Efficiency ◽  
Spatial Dependence ◽  
Stochastic Frontier ◽  
Hebei Province ◽  
Agricultural Technology ◽  
Agricultural Product ◽  
Spatial Econometric ◽  
Frontier Analysis ◽  
The Impact

In recent years, through the implementation of a series of policies, such as the delimitation of major grain producing areas and the construction of advantageous and characteristic agricultural product areas, the spatial distribution of agriculture in China has changed significantly; however, research on the impact of such changes on the efficiency of agricultural technology is still lacking. Taking 11 cities in Hebei Province as the research object, this study examines the spatial dependence of regional agricultural technical efficiency using the stochastic frontier analysis and spatial econometric analysis. The results show that the improvement in agricultural technical efficiency is evident in all cities in Hebei Province from 2008 to 2017, but there is scope for further improvement. Industrial agglomeration has statistical significance in improving the efficiency of agricultural technology. Further, there is an obvious spatial correlation and difference in agricultural technical efficiency. Optimizing the spatial distribution of agricultural production, promoting the innovation, development, and application of agricultural technology, and promoting the expansion of regional elements can contribute to improving agricultural technical efficiency.

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