scholarly journals Picloram groundwater contamination from pasture use

1969 ◽  
Vol 81 (3-4) ◽  
pp. 211-218
Author(s):  
Lii-chyuan Liu ◽  
José A. Dumas ◽  
Carmen L. Cacho

The adsorption of picloram was studied in 28 pasture soils under laboratory conditions. The adsorptive capacities of these soils were expressed in terms of the empirical constants, K and 1/n of the Freundlich equation. The calculated K values ranged from 0.269 to 1.842 for Espinosa sandy loam and Bajura clay, respectively. The 1/n values ranged from 0.27 to 1.68 for Carrizales sandy loam and Mabí clay, respectively. The K values were negatively correlated with sand content of these pasture soils, and positively correlated with organic matter content, cation exchange capacity, clay content and silt content of the soils. In a field study on picloram groundwater contamination from pasture use, picloram at 2.47 L/ha was applied twice to two pasture plots (Mabí ciay loam). Water samples were collected weekly from two wells adjacent to these pasture plots for three months after each herbicide application. All water samples were analyzed by gas chromatography. No detectable level of picloram concentration was found in any of the water samples collected after the first herbicide application. However, a very low level of picloram (2 µg/L) was detected in one of the wells 10 weeks after the second herbicide application. This finding suggests that there is little possibility that picloram will contaminate groundwater in a heavy soil such as Mabí clay loam.

2008 ◽  
Vol 53 (No. 5) ◽  
pp. 225-238 ◽  
Author(s):  
N. Finžgar ◽  
P. Tlustoš ◽  
D. Leštan

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.


Weed Science ◽  
1977 ◽  
Vol 25 (2) ◽  
pp. 159-162 ◽  
Author(s):  
R. Grover

The movement of dicamba (3,6-dichloro-o-anisic acid), picloram (4-amino-3,5,6-trichloropicolinic acid), and 2,4-D [(2,4-dichlorophenoxy)acetic acid] was studied in five Canadian prairie soils using soil columns. The three acid herbicides showed the following general order of decreasing mobility in the five soils: Asquith sandy loam > Indian Head loam > Regina heavy clay > Weyburn Oxbow loam > Melfort loam, thus indicating an inverse relationship between adsorption and mobility. In general, the distribution coefficients (kd) were comparable to the corresponding Freundlich constants (k) and these were significantly related to the soil organic matter content, to a lesser extent to soil pH, and not correlated with soil clay content. The maximum concentrations of all three herbicides in the column effluents were well below their respective water solubilities and were inversely related to the distribution coefficients. The calculated values for the amounts of precipitation required to leach the three herbicides to a depth of 10 cm showed the following order of mobility: dicamba > picloram > 2,4-D.


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.


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.


2021 ◽  
Vol 22 (1) ◽  
pp. 74-83
Author(s):  
Nabeel Rizwan

Potassium (K) availability to plants varies with the adsorption characteristics of soil, to evaluate the adsorption capacity, five soil series of different characteristics were used. K adsorption isotherms were performed by equilibrating 2.5 g soil samples with 10 levels of K (30-300 mg kg-1) as KCl in 0.01 CaCl2 solutions and shaken for 24 h at 25oC. The amount of K adsorbed ranged from 33.2 to 94.9% of added K. Freundlich model explained K adsorption behavior better than the other two equations. Higher coefficient of regression values 0.99, 0.97 and 0.96 were recorded in Sultanpur (Silt loam), Naivela (Fine sandy loam) and Bhutesar (Clay loam), respectively. The highest 1/n value 1.54 kg mg-1 and kf value 31.47 mg kg-1 of Freundlich isotherm were observed in Sultanpur (silt loam) due to high pH, high OM and high clay contents, lowest values of constants were observed in Wajan (loamy sand) with 1/n value 0.44 kg mg-1 and kf value 0.28 mg kg-1 might be due to high EC, high CaCO3 and sand contents. The K adsorption of soil varied with physico – chemical characteristics of soil, especially clay content, alkaline pH and organic matter content.


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.


2003 ◽  
Vol 13 (2) ◽  
pp. 321-324 ◽  
Author(s):  
Robert D. Belding ◽  
Bradley A. Majek ◽  
Gail R.W. Lokaj ◽  
Jeffrey Hammerstedt ◽  
Albert O. Ayeni

Peach (Prunus persica) trees were established and grown from 1996 to 1999 at the Rutgers Agricultural Research and Extension Center, Bridgeton, N.J., to compare performance under four methods of orchard floor preparation: flat no-till, flat cultivated, mound unmulched, and mound mulched orchard floors. The experimental site was flat and the soil was a well-drained Aura gravelly sandy loam (61% sand, 31% silt, 8% clay) with a pH of 6.5, cation exchange capacity 5.7, and organic matter content of 2.0%. Soil moisture holding and gas exchange capacity determine the efficacy of mounding in peach orchards. Under these conditions, the method of orchard floor preparation had no effect on peach tree trunk cross sectional area (TCSA), fruit number per tree, fruit size, and yield. Thus, without irrigation, there was no advantage to the early performance of peach trees associated with orchard floor mounding on Aura gravelly sandy loam when situated on a flat terrain.


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.


Weed Science ◽  
1974 ◽  
Vol 22 (2) ◽  
pp. 106-110 ◽  
Author(s):  
K. E. Savage ◽  
R. D. Wauchope

The adsorption-desorption equilibria of fluometuron [1,1-dimethyl-3-(α,α,α-trifluoro-m-tolyl)urea] were studied; a slurry technique with soil at 0-bar moisture tension was used. The equilibria established with Bosket very fine sandy loam (VFSL) were evaluated by three equations. The equation best describing the adsorption isotherm was x/m = K1Ce+ K2Ce2. Successive equilibrations resulted in a shift in the equilibria toward the adsorbed state, most likeiy due to a physical change in the adsorption capacity of the soil with repeated agitation. Desorption studies with seven additional soils indicated the importance of soil organic matter content in the adsorption-desorption equilibria of fluometuron. The relationship between soil organic matter contents and the adsorption-desorption equilibrium constants was characterized by a highly significant linear correlation (r = 0.93) and the resulting regression equation: K1= 0.46 + 0.45(O.M.%). Clay content of these soils was not significantly correlated with fluometuron equilibrium constants.


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