The determination of exchangeable calcium and magnesium in carbonate soils.

1954 ◽  
Vol 5 (4) ◽  
pp. 706 ◽  
Author(s):  
BM Tucker
Keyword(s):  
Calcium Carbonate ◽  
Ammonium Chloride ◽  
Free Water ◽  
Soil Samples ◽  
Acetate Anion ◽  
Mean Values ◽  
Calcium Magnesium ◽  
Calcium And Magnesium ◽  
Better Than

The solubilities of calcium and magnesium from calcium carbonate, dolomite, and magnesite, in a normal solution of ammonium chloride in 60 per cent. ethanol, adjusted to pH 8.5 with ammonia, are the same as or a little less than those in air-free water. Such a solution is suitable for the extraction of exchangeable metal cations from soil samples containing these carbonates. A single extraction yields a solution in which calcium, magnesium, sodium, and potassium may all be determined. Ammonium chloride is better than the acetate because there appears to be a specific solution effect associated with the acetate anion. The amounts of calcium and magnesium extracted by this solution from soil samples presumed to be in equilibrium with, but not containing, carbonates, are not altered by the addition of excess calcium carbonate or dolomite. An examination of 18 carbonate soils gave mean values of 16.5 m-equiv. of calcium and 11.7 of magnesium per 100 g of sample compared with 16.4 and 11.7 m-equiv. respectively by a double leaching method with normal sodium chloride solution.

Minerals in Feeds by Atomic Absorption Spectrophotometry

1967 ◽  
Vol 50 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Mary Heckman
Keyword(s):  
Sample Preparation ◽  
Atomic Absorption ◽  
Atomic Absorption Spectrophotometry ◽  
Absorption Spectrophotometry ◽  
Wet Digestion ◽  
Dry Ashing ◽  
Mineral Mixture ◽  
Calcium Magnesium ◽  
Calcium And Magnesium

Abstract Seventeen laboratories collaborated in the study of analysis of feeds for calcium, magnesium, zinc, manganese, iron, and copper by atomic absorption spectrophotometry. Six feeds and one mineral mixture were analyzed; both dry ashing and wet digestion were used to prepare samples. Three feeds were in the form of solutions to eliminate sample preparation as a variable. Strontium and lanthanum were added to the feed to eliminate phosphorus interference and results were compared. Results indicate that the method is suitable for calcium and magnesium. Further work is needed on the determination of zinc, manganese, iron, and copper.

Determination of Organic Acids in the Presence of Metal Ion

1989 ◽  
Vol 72 (5) ◽  
pp. 775-776 ◽  
Author(s):  
Masamichi Koseki ◽  
Iwao Takahashi ◽  
Tetsuko Yasuno ◽  
Shuzo Ogino ◽  
Yuko Tsuda ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Organic Acids ◽  
Metal Ion ◽  
Magnesium Ions ◽  
Ph Adjustment ◽  
Aluminum Ions ◽  
Calcium Magnesium ◽  
Calcium And Magnesium ◽  
Calcium And Magnesium Ions

Abstract The recovery of organic acids: citric, tartaric, fumaric, succinic, and malic, was examined by liquid chromatography in the presence of calcium, magnesium, or aluminum ions. Calcium and magnesium ions, i.e., ions of valence +2, did not interfere in determinations of the organic acids examined here. These organic acids could be determined without interference from aluminum ion by pH adjustment of the solutions to pH 2.

scholarly journals Distribution of extractable calcium, magnesium, potassium, and sodium in various depths of some virgin peat soils

1956 ◽  
Vol 28 (1) ◽  
pp. 237-247
Author(s):  
Armi Kaila ◽  
Jaakko Kivekäs
Keyword(s):  
Ammonium Chloride ◽  
Negative Correlation ◽  
Magnesium Content ◽  
Surface Layers ◽  
Peat Soils ◽  
Calcium Magnesium ◽  
Calcium And Magnesium ◽  
Surface Vegetation

It has been attempted in the present paper to study the distribution of plant available calcium, magnesium, and potassium in various depths of 25 virgin peat lands. The amounts of these cations extractable by 1 N ammonium chloride are supposed to give a rough estimation on the available content of the nutrients. Also the quantities of extracted sodium are reported. It has been found that the percentic content of these cations in the surface vegetation are higher than in the peat. Particularly marked is the accumulation of potassium in living plants and, although in a less degree, in the surface layers of peat. The variation in the distribution of the extractable amounts of the cations in various depths of the peat lands is considerable. A significant correlation exists between the depth and the magnesium content, and a negative correlation between the depth and the amount of extractable potassium. So far as the amount of cations extracted by 1 N ammonium chloride represents nutrients available for plants, calcium and magnesium are not generally minimum factors in peat soils, whereas in most soils the sources of potassium probably will be depleted by the first crops.

The comparative effects of exchangeable calcium, magnesium, and sodium on some physical properties of red-brown earth subsoils. I. Exchange reactions and water contents for dispersion of Shepparton soil

Soil Research ◽  
1973 ◽  
Vol 11 (2) ◽  
pp. 143 ◽  
Author(s):  
AC Bakker ◽  
WW Emerson ◽  
JM Oades
Keyword(s):  
Physical Properties ◽  
Water Content ◽  
Ammonium Chloride ◽  
Clay Fraction ◽  
Exchange Reactions ◽  
Exchangeable Calcium ◽  
Soil Calcium ◽  
Calcium Magnesium ◽  
Calcium And Magnesium ◽  
Water Contents

The susceptibility to waterlogging of red-brown earth subsoils is discussed. One of these, Shepparton, has been leached with chloride solutions of given SAR, in the range 0-7, the last solution being 1 mM in calcium or magnesium. The soil was then extracted with neutral lM ammonium chloride and the displaced cations measured. The exchange of sodium for both calcium and magnesium was similar, following the Gapon equation except at very low SAR values. Some potassium and sodium was extracted from calcium and magnesium soils. Shepparton soil of known SAR was remoulded over a range of water contents and synthetic aggregates formed. The percentage of the clay fraction which dispersed from the aggregates was measured. The water content for perceptible dispersion of magnesium soil was only about half that of calcium soil, the water contents being near the 15 bar and 0.1 bar values respectively for unsheared soil. The water content for dispersion decreased sharply with increasing SAR of the soil. Calcium-sodium soil with an ESP of 3.5 dispersed at the same water content as magnesium soil. Possible reasons for the enhanced dispersion of sheared, wet magnesium soil compared with similar calcium soil are discussed.

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

Screening and antimicrobial activity of actinomycetes isolated from the rhizosphere of Clitoria ternatea

2016 ◽  
Vol 1 (01) ◽  
Author(s):  
Vemavarapu Bhaskara Rao ◽  
Kandlagunta Guru Prasad ◽  
Krishna Naragani ◽  
Vijayalakshmi Muvva
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Calcium Carbonate ◽  
Rhizosphere Soil ◽  
Soil Samples ◽  
Antimicrobial Spectrum ◽  
Clitoria Ternatea ◽  
Primary Screening

The air dried rhizosphere soil samples pretreated with calcium carbonate was employed for the isolation of actinomycete strains. Serial dilution plate technique was used for the isolation of actinomycetes. A total of 20 actinomycete strains designated as BS1-BS20 were isolated from the rhizosphere of medicinal plant Clitoria ternatea. All the 20 strains were subjected to primary screening for antimicrobial activity. Among the 20 strains screened, 10 strains exhibited high antimicrobial spectrum against Staphylococcus aureus, Escherichia coli and Candida albicans.

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