scholarly journals On the pre-treatment of samples of heavy clay soil for determinations by the pressure membrane apparatus

1961 ◽  
Vol 33 (1) ◽  
pp. 153-158
Author(s):  
Reijo Heinonen
Keyword(s):  
Clay Soil ◽  
Soil Samples ◽  
Membrane Apparatus ◽  
Glacial Clay ◽  
Heavy Clay ◽  
Pre Treatment

The method of pre-treatment of soil samples should be chosen in each case according to the purpose of study, keeping in mind the slow reversibility of the wetting undergone by heavy glacial clay. In general, it is recommended that the air-dry samples ground to 2 mm should be soaked for three weeks prior to determinations by the pressure membrane apparatus. If it is desired to make direct determinations, grinding to pass 0.6 mm appears to be conducive to good wetting, in the case of topsoils.

scholarly journals Magnesium-supplying power of some Finnish mineral soils

1973 ◽  
Vol 45 (3) ◽  
pp. 319-324
Author(s):  
Armi Kaila ◽  
Helinä Kettunen
Keyword(s):  
Clay Soil ◽  
Total Yield ◽  
Fine Sand ◽  
Soil Samples ◽  
Silty Clay ◽  
Sand Soil ◽  
Rye Grass ◽  
Heavy Clay ◽  
Initial Content ◽  
Mineral Soils

Uptake of magnesium from a sand, fine sand, muddy clay, silty clay and heavy clay soil under exhaustive cropping with perennial rye grass was studied in green house. An application of 0.5 g Mg as MgSO4 ∙ 7 H2O per the 5-liter pots increased slightly the total yield of rye grass shoots and markedly the amount of Mg harvested in the shoots from the sand and fine sand soils with an initial content of only 14 and 37 ppm exchangeable Mg, respectively. No respond to the application of Mg was detected in the silty clay and heavy clay soils which contained exchangeable Mg 226 and 910 ppm, respectively. The muddy clay soil contained 137 ppm exchangeable Mg, and the application of Mg markedly increased the amount of Mg harvested in the shoots, but brought about a decrease in the yield of shoots. The amount of Mg harvested in the shoots without the application of Mg was only in the sand and fine sand soils higher than the original content of exchangeable Mg. Yet, in all soils except in the muddy clay, the decrease in the content of exchangeable Mg during the cropping was lower than the amount of Mg harvested. This was taken to indicate that some release of nonexchangeable Mg did occur during this trial. According to a rough estimation this mobilization of Mg varied from 0 to 60 ppm, whereas the corresponding release of nonexchangeable K was 500–1000 ppm, except in the sand soil. The »exhaustion Mg», or the sum of Mg harvested in the shoots of rye grass and the exchangeable Mg in the soil after cropping, was in all soils of the same order as the amount of Mg extracted by 0.05 N or 0.1 N HCI from the original soil samples.

Screening of Actinomycetes For α-amylase Inhibitors Production

2019 ◽  
Vol 15 (1) ◽  
pp. 41-45
Author(s):  
Shivabai Chandwad ◽  
Sudhakar Gutte
Keyword(s):  
Inhibitory Activity ◽  
Enzyme Inhibitors ◽  
Spectroscopic Method ◽  
Solid Material ◽  
Soil Samples ◽  
Assay Method ◽  
Novel Drugs ◽  
Pre Treatment ◽  
Diabetic Treatment ◽  
Amylase Inhibitors

Background:Diabetes mellitus is the most common and fastest growing disease in the world. One of the therapies to treat diabetes is the inhibition of α-amylase activity by inhibitors from microbial and plant source. Actinomycetes are potential sources of enzyme inhibitors, drugs, amino acids, vitamins etc.Objective:Our work mainly highlights the isolation of actinomycetes from soil samples of different habitats and screening of α -amylase inhibitors.Methods:Actinomycetes were isolated from soil samples of different habitats by different methods; these include a variety of pre-treatment of soil samples in combination with an appropriate supplement medium with selective antibacterial agents. Isolated actinomycetes grown in fermentation condition and metabolites were extracted with Isopropyl alcohol and concentrated to obtain solid material. The extract of each isolate was tested for α -amylase inhibition using starch Iodine plate method and DNS- spectroscopic method.Results:Total 110 actinomycetes strains were isolated from various sources. Among 110 extracts of actinomycetes, eight extracts have shown positive results for α-amylase inhibition in starch Iodine plate assay method. Extracts selected from primary results were used for the confirmation of inhibitory activity using DNS- spectroscopic method. Out of eight extracts, six extracts showed Porcine pancreatic α -amylase inhibitory activity ranging from 40-86%. The actinomycetes strains that produce α -amylase inhibitory activity are A-24, A-29, B-5, B-18, C-15 and D-24.Conclusion:These results show that actinomycetes are a potential source for α -amylase inhibitors, which may lead to valuable novel drugs for diabetic treatment.

Investigation into the effect of tillage on solute movement to drains through a heavy clay soil

2006 ◽  
Vol 15 (2) ◽  
pp. 94-100 ◽  
Author(s):  
C.D. Brown ◽  
V.L. Marshall ◽  
A. Deas ◽  
A.D. Carter ◽  
D. Arnold ◽  
...  
Keyword(s):  
Clay Soil ◽  
Heavy Clay ◽  
Solute Movement

Investigations in crop husbandry. III. Effect of time of application of sulphate of ammonia to wheat

1936 ◽  
Vol 26 (2) ◽  
pp. 316-327 ◽  
Author(s):  
F. H. Garner ◽  
H. G. Sanders
Keyword(s):  
Field Experiments ◽  
Clay Soil ◽  
Foot Rot ◽  
Plant Establishment ◽  
Poor Condition ◽  
Time Of Application ◽  
Gravelly Soil ◽  
Heavy Clay ◽  
Crop Husbandry

1. Over a period of six years seven field experiments were carried out to study the effect of the time of application of sulphate of ammonia to autumn-sown wheat.2. Three experiments were located on light gravelly soil which had been farmed highly for some years, and in those three cases sulphate of ammonia decreased yield, irrespective of time of application; the reduction in yield was of the order of 10 per cent. and is ascribed to more lodging and greater incidence of “foot-rot”.3. Three experiments were located on heavy clay soil in poor condition; in these sulphate of ammonia gave percentage increases in yield of 18, 20 and 7.4. Evidence is produced that early dressings of sulphate of ammonia do not affect germination or plant establishment, but that they tend to increase tiller formation by the end of February.

Shrinkage of artificially dried soil samples collected at different depths in a clay soil

1980 ◽  
Vol 143 (5) ◽  
pp. 518-523
Author(s):  
G. Petruzzelli ◽  
M. Pagliai ◽  
G. Guidi
Keyword(s):  
Clay Soil ◽  
Soil Samples ◽  
Different Depths

scholarly journals Reclamation of a Saline-Sodic Soil by Use of Molasses and Distillery Slops

1969 ◽  
Vol 50 (3) ◽  
pp. 209-217
Author(s):  
Raúl Pérez Escolar
Keyword(s):  
Puerto Rico ◽  
Organic Acids ◽  
Clay Soil ◽  
Mass Action ◽  
Soil Reclamation ◽  
Exchangeable Sodium ◽  
Dry Period ◽  
Action Effect ◽  
Saturation Extract ◽  
Heavy Clay

Data are presented on a laboratory study conducted to determine the effects of the use of blackstrap molasses and rum distillery slops on the reclamation of a highly saline-alkali heavy clay soil of southwestern Puerto Rico. The study revealed that even the lowest levels of distillery slops and diluted molasses, around 2.3 acre-inch, were sufficient to lower the conductivity of the soil-saturation extract from 67 mmhos/cm. to less than 3, and the exchangeable sodium percentage from 43 to less than 1 percent. It is believed that most of the Ca and Mg found in leachates of columns treated with the most slops or molasses may be attributed to the production of organic acids during the decomposition of slops and molasses. These organic acids rendered soluble the soil-free CaCO3 and MgCO3, widening the Ca and Mg:Na ratio to substitute the sodium by a mass action effect. Subjecting the soil to a dry period in between, the 6 and 7 acre-feet of water did not alter the movement of water and resulted in a complete soil reclamation.

scholarly journals Surface irrigation with saline water on a heavy clay soil in the Medjerda Valley, Tunisia.

1967 ◽  
Vol 15 (4) ◽  
pp. 281-303
Author(s):  
J.A. Van 't Leven ◽  
M.A. Haddad
Keyword(s):  
Electrical Conductivity ◽  
Clay Soil ◽  
Saline Water ◽  
Surface Irrigation ◽  
Soil Extracts ◽  
Fallow Period ◽  
Salinity Effects ◽  
Heavy Clay ◽  
Winter Crops ◽  
Resting Period

On a clay soil rich in lime, with drain spacings of 30 and 60 m, one section (A) after four crops of artichokes over a two-year period, with fairly intensive irrigation with saline water (approx 700 mm annually) showed no harmful salinity effects; in the upper 120 cm the electrical conductivity of soil extracts (EC) seldom exceeded five. On section B, with well-distributed irrigation, which was not intensive except for tomatoes in one summer, salinity was fairly uniform in the profile (EC 4-6). In section C, under continuous lucerne and with 1000-1200 mm water annually, salinity increased, especially with depth, and a fallow period was needed. In section D, under four artichoke crops followed by maize, with more intensive irrigation than in A and B, EC of the 80-120 cm layer was 7-8, and maize growth was retarded slightly. In addition to fallowing, the inclusion in rotations of winter crops and of perennials with a resting period in summer, e.g. artichokes, is recommended. A drain spacing of 60 m was adequate. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Ethylene: A Witchweed Seed Germination Stimulant

Weed Science ◽  
1975 ◽  
Vol 23 (5) ◽  
pp. 433-436 ◽  
Author(s):  
Robert E. Eplee
Keyword(s):  
United States ◽  
Seed Germination ◽  
Clay Soil ◽  
Soil Surface ◽  
Field Studies ◽  
The United States ◽  
Major Contributor ◽  
Single Treatment ◽  
Striga Asiatica ◽  
Heavy Clay

Ethylene gas (C2H4) was found to stimulate the germination of witchweed [Striga asiatica(L.) O. Kuntze] seeds. Ethylene diffuses greater than 120 cm horizontally from point of injection and more than 90 cm below the soil surface. Rates of 0.42 kg/ha induced germination of witchweed seeds in sandy soil; but 1.1 kg/ha is required on a heavy clay soil. Witchweed seeds respond to ethylene after a period of preconditioning that is necessary to break dormancy. Under field conditions in the Carolinas, maximum response of seeds to ethylene occurs between late April and late July. Field studies indicate a 90% reduction in viable witchweed seeds occurs where a single treatment with ethylene has been applied. The use of ethylene appears now to be a major contributor toward the eventual eradication of witchweed from the United States.

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