scholarly journals STRONTIUM CONTENT IN SANDY SOILS IN AGRICULTURE FIELDS (CASE STUDY: MOUNDOU, CHAD)

AGROFOR ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Kamssou KOI ◽  
Victor NAGORNY ◽  
Otilija MISECKAITE ◽  
Yuri MAZHAYSKY

During evaluation of physical and chemical properties of sandy soils and theirfertility in Southern part of Republic of Chad it has been revealed that some soilshave very high content of strontium. Its content varies from 10 to 270 mg/kg ofsoil depending on type of soil, depth of soil layers, clay and organic content.Strontium content negatively correlates with total content of calcium andphosphorus in layers of soil. Low CEC (CEC - Cation-exchange capacity) of soilmay be a reason of possible translocation of strontium from higher to lower layersof soils. Strontium content in soils do not relates with level of radioactivity of soilmeasured. The highest content of strontium has been found in soils developed onsome eolian and colluvio-alluvium deposits. Some researchers hypothesize thatsome endemic and chronic diseases such as Kashin-Beck disease, `Dysostosisenchondralis endemic`, endemic hoiter, osteoarthritis might be caused by highcontent of strontium in water and plant foods contaminated with it. Absence ofconsensus on etiological factors of these diseases confirms that it is worthconsidering necessity of further studies of different affects of high content ofstrontium in water and foods on human health directly or indirectly throughcausing misbalance in mineral nutrition.

Author(s):  
Vítězslav Vlček ◽  
Miroslav Pohanka

Soil samples (n = 11) were collected in the chernozem areas of the Czech Republic (the Central Europe) from the topsoil and used as representative samples. All sampling areas have been used for agricultural purposes (arable soil) and they were selected as typical representatives of agricultural soil. These samples represented the soil with same genesis (to reduction differencies between soil types) but with different soil properties (physical and chemical). Complete chemical and physical analyses were made for confirmation of copper adsorption on solid phase: we analysed the particle size distribution, content of oxidizable carbon (Cox), the cation exchange capacity (CEC), supply of exchange calcium, magnesium, sodium, phosphorus and potassium, soil reaction and the total supply of Fe, Al, Mn, Ca, Mg, K, P and N. The strongest simple correlation between analysed soil properties and copper concentration had content of available magnesium (r = 0.44) and available phosphorus (r = −0.51). In the case of multiple correlations (i. e. collective influence of multiple soil properties) had the strongest influence combination of clay, soil reaction, total content of phosphorus, available magnesium and available phosphorus. The main influence of phosphorus and magnesium is evident. We suppose that copper and phosphorus enter into specific complex. Influence of these five soil properties can explain 92.7 % (r = 0.927) changes in the content of copper changes in the experiment.


Soil Systems ◽  
2020 ◽  
Vol 4 (2) ◽  
pp. 25
Author(s):  
Ehsan Zare ◽  
Nan Li ◽  
Tibet Khongnawang ◽  
Mohammad Farzamian ◽  
John Triantafilis

The clay alluvial plains of Namoi Valley have been intensively developed for irrigation. A condition of a license is water needs to be stored on the farm. However, the clay plain was developed from prior stream channels characterised by sandy clay loam textures that are permeable. Cheap methods of soil physical and chemical characterisations are required to map the supply channels used to move water on farms. Herein, we collect apparent electrical conductivity (ECa) from a DUALEM-421 along a 4-km section of a supply channel. We invert ECa to generate electromagnetic conductivity images (EMCI) using EM4Soil software and evaluate two-dimensional models of estimates of true electrical conductivity (σ—mS m−1) against physical (i.e., clay and sand—%) and chemical properties (i.e., electrical conductivity of saturated soil paste extract (ECe—dS m−1) and the cation exchange capacity (CEC, cmol(+) kg−1). Using a support vector machine (SVM), we predict these properties from the σ and depth. Leave-one-site-out cross-validation shows strong 1:1 agreement (Lin’s) between the σ and clay (0.85), sand (0.81), ECe (0.86) and CEC (0.83). Our interpretation of predicted properties suggests the approach can identify leakage areas (i.e., prior stream channels). We suggest that, with this calibration, the approach can be used to predict soil physical and chemical properties beneath supply channels across the rest of the valley. Future research should also explore whether similar calibrations can be developed to enable characterisations in other cotton-growing areas of Australia.


1970 ◽  
Vol 56 (1) ◽  
pp. 113-133 ◽  
Author(s):  
K. H. Fantes

Antiviral interferon activity in any one species can be exhibited by a variety of substances that differ in their physical and chemical properties, but the nature of these differences is not understood. Conditions that can lead to the formation of diverse types of interferons have been outlined. Reasons have been adduced why, for certain purposes, purification of interferons is desirable or even necessary, and examples have been presented to show how and to what extent this has been achieved. In spite of some very high purification factors, not a single interferon has been obtained as a pure substance. Therefore, all available knowledge of physical and chemical properties has been obtained by indirect means.


Author(s):  
Juliany Barbosa de Pinho ◽  
Aloisio Bianchini ◽  
Pedro Silvério Xavier Pereira ◽  
Letycia Cunha Nunes ◽  
Rodrigo Fernandes Daros ◽  
...  

From the pyrolysis process, biochar is a carbon rich and recalcitrant organic material with potential for long term carbon sequestration because of its aromatic structure. However, the physical and chemical properties of the biochar vary due to the diversity of raw material and the conditions of production. The present study aimed to evaluate the biochar from the sugarcane bagasse at different temperatures and under two conditions of pyrolysis. The biochar was produced at two final temperatures 200°C (1 hour); 250°C (1h) and 250°C (2h), with pyrolysis of an oxidizing and non-oxidizing atmosphere for both. PH, cation exchange capacity (CTC), carbon content (C), Nitrogen (N), hydrogen (H), H:C, C:N and ash ratios were evaluated. The contents of C, H, N and the atomic ratios H:C and C:N were higher in Biochar produced in a non-oxidizing atmosphere (BNO). However, the content of ash, pH and CTC were higher in Biochar produced in oxidizing atmospheres (BO). One can conclude the direct influence of the pyrolysis condition.


2018 ◽  
Vol 151 (1) ◽  
pp. 18-34 ◽  
Author(s):  
Małgorzata Poniewozik ◽  
Josef Juráň

Background and aims – Phytoplankton samples were taken from a periodic, small and very shallow former clay-pit pond in eastern Poland near Lublin city. Diversity of the euglenophyte community was assessed during the period 2002–2004 and in 2014. Methods – Water samples were collected with a 20 µm plankton net and with a slime aspirator (20 ml capacity) from the surface of the bottom. One aliquot of each sample was fixed for SEM observation; the fresh part of the sample was analysed using light microscope. Physical and chemical properties of the water (pH, temperature, conductivity, phosphates and ammonium salt contents) were measured. Diversity indices were calculated (Shannon-Wiener, evenness, Margalef and Simpson) and UPGMA cluster analysis was applied to discern differences among euglenoid assemblages.Key results – In total, 63 euglenophyte taxa were found. The euglenophyte community was dominated by species belonging to the Trachelomonas genus (29 taxa). The most abundant and constant component were widespread and common species such as T. caudata, T. hispida, T. intermedia, T. volvocina and T. volvocinopsis. They usually occurred in very high densities. We also found some rarely reported euglenophytes including Euglena granulata, Trachelomonas lemmermannii, and T. sydneyensis. Conclusions – Euglenophytes were, with a few exceptions, the only group inhabiting the pond. Representatives of other groups such as diatoms or Scenedesmus species were recorded only occasionally. Nearly half of the taxa that were recorded in the first period (2002–2004) were found again after ten years. Of special concern was taxa belonging to the genus Trachelomonas. Trachelomonads, although known to represent taxa preferring waters moderately rich in nutrients, were very numerous in the investigated pond, which was enriched in phosphorus and nitrogen compounds.


2014 ◽  
Vol 979 ◽  
pp. 440-443
Author(s):  
W. Siriprom ◽  
K. Teanchai ◽  
S. Kongsriprapan ◽  
J. Kaewkhao ◽  
N. Sangwaranatee

The chemical and physical properties of topsoil and subsoil which collected from the cassava cropping area in Chonburi Province have been investigated. The characterization of both soil sample were used X-Ray Diffraction (XRD), Energy Dispersive X-Ray Fluorescence (EDXRF) while FTIR used to confirmed the formation of intermolecular bonding and Thermo-Gravimetric Analysis (TGA) used for investigated the crystalline. It was found that, the XRD pattern indicated quartz phase. The chemical composition by XRF reported that the soils samples consist of Si, Al, Ca, Fe, K, Mn, Ti, Cr, Zn, Ag and Cu. and TGA results, noticed that the removal of moisture and organics material.


AGRICA ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 17-21
Author(s):  
Paulus O Lana ◽  
Charly Mutiara

This study aims to determine the effect of bokashi fertilizer dosage on the physical and chemical properties of soil on tomato plants and the optimum dose of bokashi fertilizer which can provide the best influence on the physical and chemical properties of the soil. The research design used was a randomized block design (RBD) with a single factor pattern consisting of five treatments namely B0 = 0 tons ha-1 bokashi fertilizer (control), B1 = 5 tons ha-1 bokashi fertilizer, B2 = 10 tons ha-1 bokashi fertilizer, B3 = 15 tons ha-1 bokashi fertilizer, B4 = 20 tons ha-1 bokashi fertilizer. The observation variables in this study were soil volume/bulk density (gr /cm3), total soil pore space (%), N- total soil, available P-soil, available K-soil, soil C-organic, and soil pH. The results showed that the administration of bokashi fertilizer was able to improve the physical properties of soil in tomato plants, namely the weight of the soil volume decreased by 1,120 gr / cm³, water holding capacity increased by 30.24%, and soil pore space increased by 57.74%, so that the soil aggregate became good Giving doses of bokashi fertilizer can improve soil chemical properties in tomato plants, namely C-organic 0.91% very low, N-total soil 0.32% medium, P-available 37.25 ppm very high, and K-available 425.64 ppm very high and soil pH to 6.81 neutral. The supply of 20 tons/ha of bokashi fertilizer can improve soil physical and chemical properties optimally in tomato plants.


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