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

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.

2016 ◽  
Vol 8 (2) ◽  
pp. 229-235
Author(s):  
A. F. M. Sanaullah ◽  
M. Akhtaruzzaman ◽  
M. A. Uddin

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.


1969 ◽  
Vol 57 (4) ◽  
pp. 286-293 ◽  
Author(s):  
L. C. Liu ◽  
H. R. Cibes-Viadé

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.


2014 ◽  
Vol 28 (4) ◽  
pp. 459-469
Author(s):  
Zaffar Malik ◽  
Muhammad Akbar Malik ◽  
Zong Yu-Tong ◽  
Lu Sheng-Gao

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.


Weed Science ◽  
1975 ◽  
Vol 23 (2) ◽  
pp. 148-154 ◽  
Author(s):  
W. C. Carlson ◽  
E. M. Lignowski ◽  
H. J. Hopen

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.


1969 ◽  
Vol 53 (2) ◽  
pp. 113-117
Author(s):  
Raúl Pérez Escolar ◽  
M. A. Lugo López

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.


Weed Science ◽  
1970 ◽  
Vol 18 (4) ◽  
pp. 470-474 ◽  
Author(s):  
L. C. Liu ◽  
H. Cibes-Viadé ◽  
F. K. S. Koo

The adsorption of 2-(ethylamino)-4-(isopropylamino)-6-(methylthio)-s-triazine (ametryne) and 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron) varied greatly among 34 Puerto Rican soils was studied using the agitated slurry technique. Adsorption was expressed as a distribution coefficient (Kd), which is the ratio of the amount of herbicide adsorbed to the amount in the equilibrium solution. In general, diuron was adsorbed to a greater degree than ametryne. Adsorption of ametryne was positively correlated with organic matter and silt content but negatively correlated with pH of the soil. The inclusion of soil pH in a multiple regression analysis contributed the highest increase in explanation for adsorption of ametryne. Adsorption of diuron was highly correlated with organic matter content and cation exchange capacity. A correlation was found between adsorption of diuron and content of magnesium, and soil texture. Cation exchange capacity was the only inclusion soil property which, in addition to organic matter, significantly contributed to the adsorption of diuron. Temperature appeared to have a greater effect on the adsorption of diuron than on the adsorption of ametryne. Conversely, the effect of pH on the adsorption of ametryne was significantly greater than that of diuron.


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