scholarly journals Availability of Moisture in Aggregates of Various Sizes in a Typical Ultisol and a Typical Oxisol of Puerto Rico

1969 ◽  
Vol 53 (2) ◽  
pp. 113-117
Author(s):  
Raúl Pérez Escolar ◽  
M. A. Lugo López
Keyword(s):  
Puerto Rico ◽  
Cation Exchange Capacity ◽  
Organic Matter Content ◽  
Aggregate Size ◽  
Clay Content ◽  
Exchange Capacity ◽  
Matter Content ◽  
Available Water ◽  
The Individual ◽  
Very High

Data are presented in this paper on the availability of moisture in Catalina clay, an Oxisol, and Cialitos clay, an Ultisol. The soils are very high in clay content and fairly high in organic-matter content. Catalina clay is high in free iron oxides with 18.2 percent, while Cialitos clay has 13 percent. Striking differences are evident as to cation exchange capacity with values of over 20 meq. for Cialitos and only around 12 meq. for Catalina. Both soils have low available water-supplying power. However, when the individual aggregates are considered, the smaller ones retain larger volumes of available water than the larger ones. This is so because moisture retained at higher tensions decreases with decreasing aggregate size, while that retained at lower tensions increases with decreasing aggregate size. These results are explained on the basis of the larger volume of small pores in larger aggregates and the larger voids created in-between smaller aggregates.

Uptake, Translocation, and Adsorption of Pronamide

Weed Science ◽  
1975 ◽  
Vol 23 (2) ◽  
pp. 148-154 ◽  
Author(s):  
W. C. Carlson ◽  
E. M. Lignowski ◽  
H. J. Hopen
Keyword(s):  
Avena Sativa ◽  
Cell Walls ◽  
Cation Exchange Capacity ◽  
Organic Matter Content ◽  
Clay Content ◽  
Exchange Capacity ◽  
Matter Content ◽  
Soil Organic Matter Content ◽  
Seed Zone ◽  
Highly Correlated

Pronamide [3,5-dichloro-N-(1,1-dimethyl-2-propynyl)benzamide] was most phytotoxic to oat (Avena sativaL.) when placed in the seed zone and to quackgrass (Agropyron repens(L.) Beauv.), when placed in the rhizome zone. Inhibition of part of the buds by pronamide on detached quackgrass rhizome sections did not influence other buds. Foliar applications of pronamide were not phytotoxic to established oat or quackgrass. Foliar-applied14C-pronamide showed little uptake by quackgrass. Application to the roots of established plants showed rapid root uptake and movement to the foliage.14C-pronamide was rapidly absorbed by oat seedlings for the first 0.5 hr and subsequently at a much slower rate. Over 60% of the pronamide taken up after 1 hr was exchangeable. Pronamide was adsorbed to the cell walls of treated roots, but little was associated with nuclear, mitochondrial, microsomal, or soluble protein fractions. Pronamide was adsorbed to varying degrees depending on soil type. Adsorption was more highly correlated with soil organic matter content than with cation exchange capacity, clay content, or pH.

scholarly journals Evaluation of the lime requirement of tropical soils in terms of other soil characteristics

1969 ◽  
Vol 36 (2) ◽  
pp. 155-160
Author(s):  
M. A. Lugo López ◽  
F. Abruña ◽  
J. Roldán
Keyword(s):  
Cation Exchange ◽  
Clay Mineral ◽  
Cation Exchange Capacity ◽  
Ph Value ◽  
Organic Matter Content ◽  
Clay Content ◽  
Tropical Soils ◽  
Exchange Capacity ◽  
Matter Content ◽  
Significant Regression

The quantity of limestone required to bring the pH of various acid Puerto Rican soils to 6.5 was investigated and found to vary from several hundred to several thousands pounds per acre. To investigate the relation of clay-mineral type, clay content, cation-exchange capacity, organic-matter content, and pH to lime requirement, these properties were determined for several soils. A highly significant regression of lime requirement on pH was obtained which can be expressed by the equation: Y = 18.39 — 3.196 X, where Y is the lime requirement and X is the pH value. Multiple regressions including other factors did not significantly increase the variability which could be explained on terms of the first regression. Further analysis were made by arranging the data according to the predominant clay mineral. For kaolinitic soils highly significant correlations were obtained between lime requirement and either pH or cation exchange capacity. The regressions were: (a) Y = 15.26 — 2.632 pH, and (b) Y = 3.048 + 0.5774 (cation-exchange capacity), where Y is the lime requirement. A regression of lime requirement on both factors did not significantly increase the variability explained by the second equation. No significant regressions were obtained for beidellitic soils.

scholarly journals Effect of Topography and Soil Depth on Clay Content, Organic Matter Content, Active Acidity, Reserve Acidity and Cation Exchange Capacity of Some Tea Soils of Bangladesh

2016 ◽  
Vol 8 (2) ◽  
pp. 229-235
Author(s):  
A. F. M. Sanaullah ◽  
M. Akhtaruzzaman ◽  
M. A. Uddin
Keyword(s):  
Organic Matter ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Soil Depth ◽  
Organic Matter Content ◽  
Clay Content ◽  
Exchange Capacity ◽  
Matter Content ◽  
Soil Samples ◽  
Topographic Positions

Soil samples were collected from M. R. Khan tea-estate area of Moulvibazar district, Bangladesh. Organic matter, active acidity, reserve acidity, cation exchange capacity, clay content and textural class of the collected soil samples for different topographic positions and depths were determined. The percentage of sand, silt and clay varied from 59.75 to 70.50, 12.50 to 20.00 and 14.50 to 22.75, respectively. Active acidity and reserve acidity of the soils varied from 4.13 to 5.82 and 3.46 to 4.84, respectively.  Organic matter content varied from 0.37% to 1.93%. Cation exchange capacity (CEC) varied from 11.42 to 24.86 cmolKg-1. Soils were acidic in nature with considerably high reserve acidity. The measured parameters of the soil samples were plotted and analyzed with reference to topography and depth. The parameters have been found to vary with sampling sites, depths and topography.

scholarly journals Adsorption of Fluometuron, Prometryne, Sencor, and 2,4-D by Soils

1969 ◽  
Vol 57 (4) ◽  
pp. 286-293 ◽  
Author(s):  
L. C. Liu ◽  
H. R. Cibes-Viadé
Keyword(s):  
Organic Matter ◽  
Cation Exchange ◽  
Adsorption Capacity ◽  
Cation Exchange Capacity ◽  
Organic Matter Content ◽  
Clay Content ◽  
Exchange Capacity ◽  
Matter Content ◽  
The Mean ◽  
Highly Correlated

The adsorption capacity of Fluometuron, Prometryne, Sencor, and 2,4-D by 48 local soils was determined spectrophotometrically. The mean adsorptivities of the four herbicides by these soils were as follows: Prometryne 37.0 percent, Sencor 23.0 percent, Fluometuron 22.6 percent, and 2,4-D 12.4 percent. The results indicated that organic matter content was the factor most highly correlated with adsorption of these herbicides by the 48 soils. Cation exchange capacity was found to correlate significantly with adsorption of Fluometuron, Prometryne, and Sencor. Such was not the case with 2,4-D. Correlation between clay content and adsorption of Fluometuron and Sencor was statistically significant. In contrast, no significant correlation was noted between clay content and adsorption of Prometryne and 2,4-D.

scholarly journals Physical properties of unproductive soils of Northern China

2014 ◽  
Vol 28 (4) ◽  
pp. 459-469
Author(s):  
Zaffar Malik ◽  
Muhammad Akbar Malik ◽  
Zong Yu-Tong ◽  
Lu Sheng-Gao
Keyword(s):  
Tensile Strength ◽  
Physical Properties ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Organic Matter Content ◽  
Clay Content ◽  
Northern China ◽  
Exchange Capacity ◽  
Matter Content ◽  
Cracking Characteristics

Abstract .The general characteristics: particle size distribution, pH, cation exchange capacity, organic matter content, total NPK, surface area; and physical properties: coefficient of linear extensibility, tensile strength, shear strength and cracking, were investigated in unproductive soils of Northern China. Principle component analysis showed that tensile strength, cohesion, cracking characteristics, clay content, cation exchange capacity and coefficient of linear extensibility were positively correlated with each other, whereas negatively correlated with angle of friction, indicating that these properties were subjected to clay % and smectite content. These correlations might be mainly responsible for low productivity (low yields) in Northern China.

Near-infrared spectroscopy as a potential method for routine sediment analysis to improve rapidity and efficiency

1998 ◽  
Vol 37 (6-7) ◽  
pp. 181-188 ◽  
Author(s):  
Diane F. Malley
Keyword(s):  
Near Infrared ◽  
Organic Matter Content ◽  
Aggregate Size ◽  
Clay Content ◽  
Analytical Techniques ◽  
Matter Content ◽  
Near Infrared Reflectance ◽  
Organic C ◽  
Analytical Technique ◽  
Sediment Analysis

The potential for improvement in the rapidity, cost-effectiveness, and efficiency of sediment analysis by the application of near-infrared reflectance spectroscopy (NIRS) is recognized. The rapid (<2 min), non-chemical, non-destructive analytical technique of near-infrared (700–2500 nm) spectroscopy combines applied spectroscopy and complex statistics. It has been used for the experimental analysis of various constituents and functions of soils since the 1960s, and applications for the analysis of sediments are currently being explored. For application of NIRS, sediment samples require little preparation, other than drying, and the samples are not subject to the manipulations of conventional analytical techniques. The spectral information recorded in a 2 min scan can be used to predict numerous constituents and parameters on the samples once appropriate calibration equations have been prepared from sets of samples analyzed by both NIRS and conventional analytical techniques. Constituents and properties of soil and/or sediment analyzed by NIRS technology include moisture, organic matter content, organic C, CO3=, N, P, S, K, Ca, Mg, clay content, humic acids, lignin, cellulose, metal oxides, heavy metals, aggregate size, and inferred past pH of lakes. Several areas are identified where further research is needed to prepare for the application of NIRS to the routine analysis of sediments.

scholarly journals Comparative value of various methods of approximating the permanent wilting percentage

1969 ◽  
Vol 36 (2) ◽  
pp. 122-133
Author(s):  
M. A. Lugo López
Keyword(s):  
Puerto Rico ◽  
Organic Matter Content ◽  
Clay Content ◽  
Matter Content ◽  
Regression Equations ◽  
Accurate Approximation ◽  
Time Saving ◽  
Laboratory Equipment ◽  
Pressure Plate ◽  
Humid Region

Very accurate estimations of the permanent wilting percentage can be obtained for soils of all regions of Puerto Rico by use of regression equations based on the hygroscopic coefficient. Reliable estimates can also be obtained for humid-region soils by using the clay content as a basis. Attempts to correlate permanent wilting-percentage values with moisture equivalents and organic-matter content did not give such satisfactory results. The 15-atmosphere percentage as determined by using pressure plates gives an accurate approximation of permanent wilting-percentage values. It is time-saving, but initial expense in laboratory equipment is rather high. This approach is to be preferred whenever feasible. A regression equation is given relating pressure-plate values to the permanent wilting percentage. Whenever less precise estimates are acceptable and time is not a factor, advantage should be taken of the established correlation between the hygroscopic coefficient and the permanent wilting percentage.

scholarly journals Relationship of soil properties to fractionation, bioavailability and mobility of lead and zinc in soil

2008 ◽  
Vol 53 (No. 5) ◽  
pp. 225-238 ◽  
Author(s):  
N. Finžgar ◽  
P. Tlustoš ◽  
D. Leštan
Keyword(s):  
Organic Matter ◽  
Regression Analysis ◽  
Soil Organic Matter ◽  
Soil Properties ◽  
Multiple Regression ◽  
Contaminated Soils ◽  
Organic Matter Content ◽  
Clay Content ◽  
Exchange Capacity ◽  
Matter Content

Sequential extractions, metal uptake by <i>Taraxacum officinale</i>, Ruby&rsquo;s physiologically based extraction test (PBET) and toxicity characteristic leaching procedure (TCLP), were used to assess the risk of Pb and Zn in contaminated soils, and to determine relationships among soil characteristics, heavy metals soil fractionation, bioavailability and leachability. Regression analysis using linear and 2nd order polynomial models indicated relationships between Pb and Zn contamination and soil properties, although of small significance (<i>P</i> < 0.05). Statistically highly significant correlations (<i>P</i> < 0.001) were obtained using multiple regression analysis. A correlation between soil cation exchange capacity (CEC) and soil organic matter and clay content was expected. The proportion of Pb in the PBET intestinal phase correlated with total soil Pb and Pb bound to soil oxides and the organic matter fraction. The leachable Pb, extracted with TCLP, correlated with the Pb bound to carbonates and soil organic matter content (<i>R</i><sup>2</sup> = 69%). No highly significant correlations (<i>P</i> < 0.001) for Zn with soil properties or Zn fractionation were obtained using multiple regression.

scholarly journals Organic-Matter Activity of Some Typical Soils of Puerto Rico

1969 ◽  
Vol 39 (2) ◽  
pp. 65-76
Author(s):  
Fernando Abruña-Rodríguez ◽  
José Vicente-Chandler
Keyword(s):  
Organic Matter ◽  
Puerto Rico ◽  
Soil Organic Matter ◽  
Close Association ◽  
C:N Ratio ◽  
Organic Matter Content ◽  
Exchange Capacity ◽  
Matter Content ◽  
Soil Samples ◽  
Considerable Portion

The exchange capacity of the organic matter in typical soils of Puerto Rico was evaluated from: (1) The variation in the exchange capacity of soil samples following destruction of the organic matter, (2) titration curves of extracted organic matter, (3) and the correlations between exchange capacity and organic-matter content of soil samples. The first method was the most practical and gave fairly accurate results. The second method gave results which were in all cases too high. The third method, though probably the most accurate, is impractical. Results obtained with the first and third methods were similar. The exchange capacity of the organic matter varied rather widely, but was generally between 100 and 150 m.e. per 100 gm. On the average it accounted for about 25 percent of the total exchange capacity of the soils studied. The organic matter removed by flotation had the highest exchange capacity and the more readily oxidizable portions generally appeared to be the most active. This suggests the importance of conserving the more readily lost portions of the soil organic matter. A considerable portion of the soil organic matter was extremely resistant to oxidation, had a narrow C:N ratio, and apparently little exchange capacity. This suggests a close association between the organic matter and the inorganic soil colloids. The marked resistance to oxidation of a considerable portion of the organic matter may partly explain the high contents found even in continuously cultivated soils in Puerto Rico.

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