scholarly journals Predatory nematodes of the order Mononchida from riparian habitats in Bulgaria

2019 ◽  
Vol 2 ◽  
Author(s):  
Stela Dipchikova ◽  
Aleksandar Mladenov ◽  
Vlada Peneva ◽  
Stela Lazarova
Keyword(s):  
Sampling Site ◽  
Soil Samples ◽  
Riparian Zones ◽  
Vegetation Types ◽  
Biological Regulation ◽  
River Bank ◽  
Intensive Exploitation ◽  
Ulmus Laevis ◽  
Riparian Habitats ◽  
Core Soil

The riparian zones represent habitats of high and specific biodiversity; however, historically they have been subject to intensive exploitation and most of them are drastically changed. Predatory nematodes are widespread terrestrial organisms and play an important role in biological regulation of litter/soil communities. Some preliminary results on the mononchid fauna in riparian habitats in South Bulgaria are presented. Thirty-four samples were collected from 29 localities with various vegetation types in three districts: Sofia, Smolyan and Burgas. Multiple core soil samples (3 per site) were collected from each habitat (15×15 m sampling site or along the river bank) around the roots of the dominant tree at a depth of 40–60 cm and from litter. The most intensively sampled plant tree was Salix spp. (11 samples) followed by Fraxinus spp. (8), Alnus glutinosa (L.) Gaertn. (6) and Ulmus spp. (3). Nematodes were isolated from 200 g of soil (by decanting and sieving method) and 10 g of litter (Baerman funnel method), fixed, dehydrated and mounted on permanent slides. More than 90% of all soil and litter samples contained at least one mononchid genus. Six genera: Prionchulus (Cobb, 1916) Wu and Hoeppli, 1929, Clarkus Jairajpuri, 1970, Mononchus Bastian, 1865 (fam. Mononchidae), Mylonchulus Cobb, 1916 (fam. Mylonchulidae), Miconchus Andrassy, 1958 and Anatonchus Cobb, 1916 (fam. Anatonchidae) were recovered. Prionchulus spp. prevailed in litter, occurring in half of the collected samples, while Mylonchulus spp. were most common in soil samples (35%). Representatives of Clarkus and rarely Mylonchulus occurred in both litter and soil. The highest diversity of mononchids (4 genera) was detected in the rhizosphere of Ulmus laevis Pall. along a small river in Strandzha Mt. Further morphological and molecular studies on populations and species identification are envisaged.

scholarly journals Interpretaciones sobre la lluvia de polen en la región de San Luis Potosí, México

2017 ◽  
pp. 53 ◽  
Author(s):  
Socorro Lozano-García
Keyword(s):  
Cluster Analysis ◽  
Soil Samples ◽  
The State ◽  
Oak Forest ◽  
Vegetation Types ◽  
High Pollen ◽  
Clear Separation ◽  
San Luis ◽  
San Luis Potosi ◽  
San Luis Potosí

In a region located mainly in the State of San Luis Potosí, México, floristic and soil samples were taken, in order to obtain palynological spectra. The comparison between the floristic results and the palynological spectra corresponding to eight types of vegetation, shows that there are taxa such as Pinus and Quercus with a high pollen representation (RP) in most of the spectra. There were some, such as the grasses that exhibited a normal RP. Also, low values of RP were detected in some taxa typical of sucrubland. A cluster analysis was applied to forty-seven soil samples and yielded a clear separation between a) oak forest and chaparral, and b) other vegetation types.

scholarly journals Measurement of Soluble Arsenic in Soil of Bangladesh by Acid-alkali Sequential Extraction

2008 ◽  
Vol 1 (1) ◽  
pp. 92-107 ◽  
Author(s):  
Mohammad Shafiul Azam ◽  
Md. Shafiquzzaman ◽  
Iori Mishima ◽  
Jun Nakajima
Keyword(s):  
Sequential Extraction ◽  
Soil Phosphorus ◽  
Extraction Procedure ◽  
Soil Surface ◽  
Soil Samples ◽  
Wet Season ◽  
Arsenic Mobility ◽  
Reducing Conditions ◽  
Sequential Extraction Method ◽  
Core Soil

To measure easily soluble fraction of arsenic, a sequential extraction method by 0.1N HCl and 0.1N NaOH was used according to the soil phosphorus extraction procedure. The effects of reducing conditions on arsenic extraction were examined in incubation test. In high reducing conditions arsenic solubility was shown to be high and seemed to be controlled by dissolution of iron oxy-hydroxides. pH played a predominant role in determining the concentrations of soluble arsenic. Arsenic solubility could be possible at low or high pH conditions. Released arsenic in different pH and redox conditions showed that it is a part of acid extractable arsenic which is sorbed weakly on the soil surface and can be extracted during acid-alkali sequential extraction. Therefore, the method could be applicable to measure potential solubility of arsenic as a result of alteration in soil (e.g. redox, pH) and environmental factors. Sequential extraction results of the soil samples collected in dry and wet season suggested that acid-alkali extracted arsenic fractions of surface and core soil samples of paddy field were increased in wet season. They seemed to be moved with irrigation groundwater. Keywords: Acid-alkali extraction; Arsenic contamination; Soil arsenic mobility; Groundwater contamination; Paddy soil.  © 2009 JSR Publications. ISSN: 2070-0237(Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v1i1.1058  

scholarly journals Soil compaction by the tractor in spring and its effect on soil porosity 

1983 ◽  
Vol 55 (2) ◽  
pp. 91-107
Author(s):  
Erkki Aura
Keyword(s):  
Soil Compaction ◽  
Theoretical Calculations ◽  
Soil Surface ◽  
Mechanical Impedance ◽  
Soil Samples ◽  
Soil Porosity ◽  
Sowing Time ◽  
Compacted Soil ◽  
Core Soil ◽  
Porosity Measurements

The effect on soil porosity of tractor compaction of soil in the spring was studied by taking cylindrical core soil samples. The profile samples showed that the tractor most seriously compacts the soil below the harrowed layer at the depth of 10-25 cm. Soil was compacted most severely when till age and drilling were performed under wet conditions about one week be for enormal sowing time. The sub soil at the depth of 35-40 cm was compacted only under very wet conditions. The grain yield of wheat was significantly reduced when the volume of large pores was reduced to about 10 % or less. Porosity measurements showed that the severely compacted soil almost completely recovered from one spring to the next. Theoretical calculations suggested that compaction by normal traffic does not cause a shortage of oxygen at least in the inter-crumb pores of soil if the soil surface structure is not dispersed and encrusted. The decrease in crop growth by compaction is primarily due to mechanical impedance, which slows down development of the root system.

scholarly journals Assessment of Soil St ructural Stability Under Different Land Uses Using Some Predictive Indices in Abakaliki, Southeastern Nigeria

2015 ◽  
Vol 3 (1) ◽  
pp. 14-19
Author(s):  
J Nwite
Keyword(s):  
Hydraulic Conductivity ◽  
Structural Stability ◽  
Aggregate Stability ◽  
Total Porosity ◽  
Soil Samples ◽  
Fallow Land ◽  
Land Uses ◽  
Mean Weight Diameter ◽  
Core Soil ◽  
Dispersion Ratio

This study was carried out in order to assess soil structural stability under different land uses using predictive indices. Different land uses of forest land, cattle paddock, fallow land and continuously cultivated farmland were carefully identified within Abakaliki agroecology. Auger and core soil samples were collected at five sampling points using free survey technique in each land use. Core soil samples were used to determine predictive indices of bulk density, total porosity and hydraulic conductivity. Auger soil samples were bulked and used for determination of mean weight diameter (MWD), aggregate stability, dispersion ratio and particle size distribution. Data obtained were subjected to coefficient of variation (CV) analysis and standard deviation. Results showed that sand and clay fractions had little variation (%CV<7-8) but silt fraction varied moderately (%CV >28). Furthermore, bulk density, mean weight diameter, aggregate stability and hydraulic conductivity were highly varied (%CV >112-245), total porosity had moderate variation (%CV >30) and dispersion ratio, high variation (%CV >80), respectively. The different land uses are generally rated according to their performance in their structural stability using the predictive indices as forestland>cattle paddock>fallow land>farmland. It is recommended that the practice of forestry, grazing, fallowing and other management practices which encourage formation and stabilization of soil structural stability be adopted for sustenance of higher soil productivity.

PRESERVATION OF SMALL CORE SOIL SAMPLES

Soil Science ◽  
1939 ◽  
Vol 47 (5) ◽  
pp. 353-356
Author(s):  
R. W. GERDEL
Keyword(s):  
Soil Samples ◽  
Small Core ◽  
Core Soil

The occurrence and distribution of Trichodorus and Paratrichodorus spp. (Nematoda: Trichodoridae) in the Slovak Republic

Nematology ◽  
1999 ◽  
Vol 1 (6) ◽  
pp. 631-636 ◽  
Author(s):  
Marta Liskova ◽  
Dieter Sturhan
Keyword(s):  
Geographical Distribution ◽  
Dominant Species ◽  
Slovak Republic ◽  
Soil Samples ◽  
The Other ◽  
Undescribed Species ◽  
River Bank ◽  
The Family ◽  
Distribution And Ecology ◽  
First Time

AbstractThe occurrence of trichodorids in a selected range of biotopes (fields and gardens, grassland, vineyards, orchards, forests, river banks and bushland) and their geographical distribution were studied throughout Slovakia. From a total of 684 soil samples collected, trichodorids were recovered from 225 (= 33%). Although members of the family Trichodoridae were present in more than 50% of the samples from forests and river bank vegetation, the prevalence of these nematodes in other biotopes was less than 20%. Six Trichodorus species (T. primitivus, T. similis, T. sparsus, T. variopapillatus, T. viruliferus and an undescribed species) and two Paratrichodorus species (P. macrostylus and P. pachydermus) were identified. T. sparsus was the most frequently occurring species (58% of all trichodorid records); the prevalence of the other seven species each accounted for less than 10% of the records. Individual trichodorid species showed an association with characteristic types of vegetation; e.g., T. sparsus was the dominant species in forest biotopes, T. similis preferred grassland, and T. variopapillatus wet soil associated with river bank vegetation. With the exception of T. sparsus and P. macrostylus, which occurred in various types of soil (sandy to loamy-clay), the other trichodorid species were found exclusively in lighter soils (sandy to loamy-sandy). T. variopapillatus is reported from the Slovak Republic for the first time and the records of P. macrostylus occurring in various biotopes in Slovakia extends the information on geographical distribution and ecology of this rare species. Vorkommen und Verbreitung von Trichodorus und Paratrichodorus spp. (Nematoda: Trichodoridae) in der Slowakischen Republik - Das Vorkommen von Trichodoriden in verschiedenen Biotoptypen (Acker und Garten, Grasland, Weinberge, Obstanlagen, Walder und Flussufer) und ihre geographische Verbreitung in der Slowakei wurden untersucht. In 225 (= 33%) von 684 untersuchten Bodenproben waren Trichodoriden nachweisbar. Wahrend in mehr als 50% der Proben aus Waldern und von Flussufern Arten der Familie Trichodoridae vorkamen, lag der Anteil 'positiver' Proben bei anderen Biotopen unter 20%. Sechs Trichodorus Arten (T. primitivus, T. similis, T. sparsus, T. variopapillatus, T. viruliferus und eine unbeschriebene Art) und zwei Paratrichodorus Arten (P. macrostylus, P. pachydermus) wurden nachgewiesen. T. sparsus wurde am haufigsten gefunden (58% aller TrichodoridenNachweise); der Anteil der ubrigen sieben Arten lag jeweils unter 10%. Einzelne Arten zeigten eine Bevorzugung bestimmter Vegetationstypen. So war T. sparsus die dominante Art in Waldbiotopen, T. similis bevorzugte Grasland und T. variopapillatus nasse Boden unter Flussufervegetation. Mit Ausnahme von T. sparsus und P. macrostylus, die in verschiedenen Bodenarten (sandig bis lehmigtonig) auftraten, wurden die ubrigen Arten ausschliesslich in leichten, sandigen bis sandig-lehmigen Boden gefunden. T. variopapillatus wird erstmals fur die Slowakische Republik gemeldet. Die Feststellung von P. macrostylus in verschiedenen Biotopen in der Slowakei erweitert unsere Kenntnisse uber die geographische Verbreitung und Okologie dieser seltenen Art.

scholarly journals Identification and differentiation of Pseudomonas species in field samples using an rpoD amplicon sequencing methodology

2021 ◽  
Author(s):  
Jonas Greve Lauritsen ◽  
Morten Lindqvist Hansen ◽  
Pernille Kjersgaard Bech ◽  
Lars Jelsbak ◽  
Lone Gram ◽  
...  
Keyword(s):  
16S Rrna ◽  
Large Scale ◽  
Sampling Site ◽  
Amplicon Sequencing ◽  
Soil Samples ◽  
Species Differentiation ◽  
Rrna Gene ◽  
Rpod Gene ◽  
Field Samples ◽  
Pseudomonas Species

Species of the genus Pseudomonas are used for several biotechnological purposes, including plant biocontrol and bioremediation. To exploit the Pseudomonas genus in environmental, agricultural or industrial settings, the organisms must be profiled at species level as their bioactivity potential differs markedly between species. Standard 16S rRNA gene amplicon profiling does not allow for accurate species differentiation. Thus, the purpose of this study was to develop an amplicon-based high-resolution method targeting a 760 nt region of the rpoD gene enabling taxonomic differentiation of Pseudomonas species in soil samples. The method was benchmarked on a sixteen membered Pseudomonas species mock community. All 16 species were correctly and semi-quantitatively identified using rpoD gene amplicons, whereas 16S rRNA V3V4 amplicon sequencing only correctly identified one species. We analysed the Pseudomonas profile in thirteen soil samples in northern Zealand, Denmark, where samples were collected from grassland (3 samples) and agriculture soil (10 samples). Pseudomonas species represented up to 0.7% of the microbial community, of which each sampling site contained a unique Pseudomonas composition. Thirty culturable Pseudomonas strains were isolated from each grassland site and ten from each agriculture site and identified by Sanger sequencing of the rpoD gene. In all cases, the rpoD-amplicon approach identified more species than found by cultivation, including hard-to-culture non-fluorescent pseudomonads, as well as more than found by 16S rRNA V3V4 amplicon sequencing. Thus, rpoD profiling can be used for species profiling of Pseudomonas, and large scale prospecting of bioactive Pseudomonas may be guided by initial screening using this method.

scholarly journals MYCOREMEDIATION OF HEAVY METALS PRESENT IN CONTAMINATED AGRICULTURAL SOIL

2020 ◽  
Vol 21 (supplement 1) ◽  
Author(s):  
Manisha Shalini Besra ◽  
Prashant Kumar Mishra
Keyword(s):  
Heavy Metals ◽  
Soil Sample ◽  
Agricultural Soil ◽  
Sampling Site ◽  
Control Sample ◽  
Soil Samples ◽  
The Other ◽  
Mushroom Cultivation ◽  
Initial Screening ◽  
Barren Land

In this study, Mycoremediation technique was used to analyse the potential of mushroom in absorbing heavy metals from contaminated soil. A small village Sitagarha located in Hazaribag, Jharkhand was selected as sampling site. Soil sample was collected from two different sites – from field where cow manure was used as fertilizer and the other soil sample where chemical fertilizer was mixed. A control sample was also collected from nearby barren land where no cultivation was carried out since decades. After initial screening, three heavy metals Cu, Cd and Zn were selected to carry out further studies. The soil sample was processed in laboratory and analysed in AAS to detect the concentration of heavy metals. Results showed the presence of heavy metals as – Cd > Cu > Zn. Further these soil samples were mixed along with straw and spawn to prepare a mushroom cultivation bag as mushroom has the property to absorb heavy metals. The result of absorbance of heavy metals by mushroom was somewhere an indication that mycoremediation proofs to be an important tool to fight against heavy metals.

Metal accumulation by Arabidopsis halleri subsp. gemmifera at a limestone mining site

2015 ◽  
Vol 63 (2) ◽  
pp. 134 ◽  
Author(s):  
Aki Kosugi ◽  
Jun Tamaru ◽  
Kazumi Gotou ◽  
Hazuka Y. Furihata ◽  
Akifumi Shimizu ◽  
...  
Keyword(s):  
Calcareous Soil ◽  
Metal Accumulation ◽  
Rhizosphere Soil ◽  
Sampling Site ◽  
Calcareous Soils ◽  
Soil Samples ◽  
Arabidopsis Halleri ◽  
Soil Factors ◽  
Mining Site ◽  
Zn Concentration

Arabidopsis halleri subsp. gemmifera, a close wild relative of A. thaliana in eastern Asia, is an important model species of Brassicaceae used to study cadmium (Cd) and zinc (Zn) tolerance and hyperaccumulation in plants. To investigate the effects of soil factors on metal accumulation in this plant, we collected plants and rhizosphere soil samples from a limestone mining site on Mount Ibuki, and compared them with those collected from non-calcareous soil in Japan. Irrespective of the sampling site, all the plants efficiently accumulated Cd in shoot tissues. The plants growing on non-calcareous soil also accumulated Zn in shoot tissues, but shoot Zn concentration in plants growing on calcareous soils was below the level required for hyperaccumulators. The pH of calcareous soil samples was between 7.68 and 8.21. Total Zn contents were similar in calcareous and non-calcareous soils, but the amounts of Zn extractable by 0.1 M HCl were lower in calcareous than in non-calcareous soil. These results indicate that the properties of calcareous soil affect metal accumulation in plants.

Depositional history of Luna 24 drill core soil samples

1979 ◽  
Vol 44 (2) ◽  
pp. 325-334 ◽  
Author(s):  
J.N. Goswami ◽  
D. Lal ◽  
M.N. Rao ◽  
T.R. Venkatesan
Keyword(s):  
Soil Samples ◽  
Drill Core ◽  
Depositional History ◽  
History Of ◽  
Core Soil
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