Adsorption and Degradation of Chlorbromuron in Soil

Weed Science ◽  
1973 ◽  
Vol 21 (5) ◽  
pp. 416-420 ◽  
Author(s):  
K. E. Savage

The adsorption-desorption equilibria of chlorbromuron [3-(4-bromo-3-chlorophenyl)-1-methoxy-1-methylurea] in soil conformed to the Freundlich equation. Values of the constants,kandn, ranged from 4.2 to 12.3 and from 1.2 to 2.5, respectively, in eight soils. No significant linear correlation was detected between the Freundlich k values and soil texture, organic-matter content, pH, or water-holding capacity. Degradation studies were conducted using14C-carbonyl-radiolabeled chlorbromuron in soil incubated at 18 or 32 C, with and without prior autoclaving, and with and without glucose enrichment. Degradation was enhanced by the higher temperature and glucose amendment, and it was retarded by autoclaving. Thin-layer chromatography indicated no accumulation of the monomethyl or monomethoxy derivative of chlorbromuron in any of the treatments. Chlorbromuron degraded rapidly in the incubation studies. Rapid loss of phytotoxicity was also noted in a greenhouse study with cucumber (cucumis sativusL. ‘Explorer’) bioassay. Phytotoxicity from 4 ppmw chlorbromuron had diminished to a very low level after 12 weeks.

Weed Science ◽  
1975 ◽  
Vol 23 (6) ◽  
pp. 454-457 ◽  
Author(s):  
Chu-Huang Wu ◽  
Normie Buehring ◽  
J. M. Davidson ◽  
P. W. Santelmann

Soil columns and soil thin-layer chromatography were used to evaluate the mobility of napropamide [2-(α-naphthoxy)-N,N,-diethylpropionamide] in various soils. The surface-applied herbicide did not move deeper than approximately 6 cm in a Teller sandy loam soil after a water application of 10.2 cm. The Rfvalues for napropamide and two reference herbicides were in the order of fluometuron [1,1-dimethyl-3-(α,α,α-trifluoro-m-tolyl)urea] > napropamide > terbutryn [2-(tert-butylamino)-4-(ethylamino)-6-(methylthio)-s-triazine]. The mobility of each herbicide was reduced with an increase in clay and organic matter content. Carbon-14 ring labeled napropamide was used to determine the adsorption and desorption characteristics of the herbicide in various soils. The Rfvalues obtained with napropamide and each soil agreed with the adsorptive characteristics. Small applications of a muck soil to a sand (2%, w/w) significantly increased herbicide adsorption and decreased herbicide desorption.


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.


Environments ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 32
Author(s):  
María J. Carpio ◽  
María J. Sánchez-Martín ◽  
M. Sonia Rodríguez-Cruz ◽  
Jesús M. Marín-Benito

The management of large volumes of organic residues generated in different livestock, urban, agricultural and industrial activities is a topic of environmental and social interest. The high organic matter content of these residues means that their application as soil organic amendments in agriculture is considered one of the more sustainable options, as it could solve the problem of the accumulation of uncontrolled wastes while improving soil quality and avoiding its irreversible degradation. However, the behavior of pesticides applied to increase crop yields could be modified in the presence of these amendments in the soil. This review article addresses how the adsorption–desorption, dissipation and leaching of pesticides in soils is affected by different organic residues usually applied as organic amendments. Based on the results reported from laboratory studies, the influence on these processes has been evaluated of multiple factors related to organic residues (e.g., origin, nature, composition, rates, and incubation time of the amended soils), pesticides (e.g., with different use, structure, characteristics, and application method), and soils with different physicochemical properties. Future perspectives on this topic are also included for highlighting the need to extend these laboratory studies to field and modelling scale to better assess and predict pesticide fate in amended soil scenarios.


Weed Science ◽  
1983 ◽  
Vol 31 (3) ◽  
pp. 368-372 ◽  
Author(s):  
Josef Kozak ◽  
Jerome B. Weber

Adsorption of five phenylurea herbicides, metobromuron [3-(p-bromophenyl)-1-methoxy-1-methylurea], monolinuron [3-(p-chlorophenyl)-1-methoxyl-1-methylurea], linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea], chlorbromuron [3-(4-bromo-3-chlorophenyl)-1-methoxy-1-methylurea], and CGA-15646 [3-(3-chloro-4-methylphenyl)-1,1-dimethylurea] by eight selected soils of Czechoslovakia were studied. Constants from Freundlich and Langmuir equations were calculated and correlated with the major soil properties. Freundlich K values ranged from 1.84 to 128, and the Freundlich equation was better fitted to the adsorption isotherms than was the Langmuir equation. Soil organic-matter content was the most important factor influencing the range of adsorption.


2017 ◽  
Vol 41 (1) ◽  
pp. 32-41 ◽  
Author(s):  
Estêvão Vicari Mellis ◽  
José Carlos Casagrande ◽  
Marcio Roberto Soares

ABSTRACT Although nickel (Ni) has both important potential benefits and toxic effects in the environment, its behavior in tropical soils has not been well studied. Nickel adsorption-desorption in topsoil and subsoil samples of an acric Oxisol was studied at three pH values (from 3.0 to 8.0). Adsorption-desorption isotherms were elaborated from experiments with increasing Ni concentration (5 to 100 mg L-1), during 0, 4, and 12 weeks, using CaCl2 0.01 and 0.1 M as electrolytic support in order to also verify the effect of Ni-soil time contact and of ionic strength on the reaction. Experimental results of Ni adsorption fitted Langmuir model, which indicated that maximum Ni adsorption (71,440 mg kg-1) occurred at subsoil, after 12 weeks. Nickel affinity (KL) was also greater at subsoil (1.0 L kg-1). The Ni adsorption in the topsoil samples was higher, due to its lower point of zero salt effect (PZSE) and higher organic matter content. The increase in soil pH resulted in the increase of Ni adsorption. Nickel desorbed less from soil samples incubated for 4 or 12 weeks, suggesting that Ni interactions with colloidal particles increase over time. The amount of Ni desorbed increased with increasing ionic strength in both the topsoil and subsoil soil samples. Finally, adsorption-desorption hysteresis was clearly observed. Soil pH, ionic strength of soil solution and the Ni-soil contact time should be considered as criteria for selecting the areas for disposal of residues containing Ni or to compose remediation strategies for acric soils contaminated with Ni.


2018 ◽  
Vol 7 (2) ◽  
Author(s):  
. Gustian ◽  
. Burhanuddin ◽  
Wiwik Ekyastuti

Gold mining activities have negatively impacted post-mining land into poor nutrients, low pH, toxic soil, due to heavy metal content, low water holding capacity, low organic matter content and unstable land conditions. To change the tailings to be more productive many of the available technologies, such as the use of manure, compost, litter or the use of soil microbes such as mycorrhiza. The addition of manure can additionally increase nutrient available, can also improve the physical and biological properties of the soil. Alaurites moluccana (L) Wild) is one of the plants classified as a pioneer species because it can grow on critical land with low soil fertility and open soil. Research on ameliorant of tailings to increase the growth of  A. moluccana  in the nursery aims to obtain a mixture of ameliorants with the tailings to enhance the growth of A. moluccana  in the nursery. Treatment was given to the growth of seedlings of A. moluccana  using the Completely Randomized Design (RAL) exprotment method with a total of 8 treatments that included an ameliorant tailing control, tailings with ameliorant a (1: 1, 1: 2, and 1: 3), tailings with ameliorant b (1: 1, 1: 2, and 1: 3) and ultisol soil control, with each treatment repeated 5 times. Data collected were shoot hight (cm), stem diameter (mm), number of leaves and dry weight of plant. The result of tailings treatment  with addition of organic ameliorant gave a very significant effect on the growth of height, diameter, number of leaves and dry weight of the A. Moluccana.  The best media treatment for all parameters is M6 (tailings: kotoran sapi 1: 3). Although virtually all treatments with organic ameliorant  provide better results than controls without the addition of organic ameliorants.Keywords: Tailings, ameliorant, A. moluccana , organic.


Weed Science ◽  
1994 ◽  
Vol 42 (4) ◽  
pp. 635-640 ◽  
Author(s):  
Jill Schroeder

Growth chamber research was conducted to compare the persistence of chlorimuron or imazaquin in soils from 11 locations in the southern United States at 25 C. Chlorimuron at 30 ng g-1or imazaquin at 60 ng g-1of soil was incorporated throughout each soil, and soils were watered to the water holding capacity and incubated in the dark. Soil samples were taken 0, 7, 14, 28, 60, and 90 d after treatment. Amount of chlorimuron or imazaquin remaining in each soil was quantified by sicklepod or corn root length bioassay, respectively. First order regression generally fit the concentration data for each herbicide. Bioactivity and persistence of chlorimuron in the soils was related primarily to soil organic matter content. Bioactivity and persistence of imazaquin was similar among the soils.


Soil Systems ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 53
Author(s):  
Gianniantonio Petruzzelli ◽  
Francesca Pedron

The adsorption and desorption process of the tungstate ion was studied in three soils characteristic of the Mediterranean area, with particularly reference to bioavailability pathways. In the three soils examined, the tungstate adsorption was described by a Langmuir-type equation, while the desorption process showed that not all the adsorbed tungstate was released, probably due to the formation of different bonds with the adsorbing soil surfaces. The pH was found to be the main soil property that regulates the adsorption/desorption: The maximum adsorption occurred in the soil with the acidic pH, and the maximum desorption in the most basic soil. In addition, the organic matter content played a fundamental role in the adsorption of tungstate by soils, being positively correlated with the maximum of adsorption. These results indicate that the lowest bioavailability should be expected in the acidic soil characterized by the highest adsorption capacity. This is confirmed by the trend of the maximum buffer capacity (MBC) of soils which is inversely related to bioavailability, and was the highest in the acidic soil and the lowest in the most basic soil. Our data could contribute in drafting environmental regulations for tungsten that are currently lacking for Mediterranean soils.


Weed Science ◽  
1984 ◽  
Vol 32 (2) ◽  
pp. 273-278 ◽  
Author(s):  
William C. Koskinen

Adsorption and desorption of14C-methazole [2-(3,4-dichlorophenyl)-4-methyl-1,2,4-oxadiazolidine-3,5-dione] were characterized on two silt loam soils (Dundee and Palouse; 0.7 and 3.0% organic matter, respectively) using the batch equilibration technique. Freundlich adsorption isotherm coefficients (Kfand l/n) were calculated after equilibration of methazole solutions (initial concentrations = 0.11 to 4.10 nmol/ml) with soil for various times. After a rapid attainment of an apparent equilibrium,14C- concentration in solution for the Palouse soil decreased at a low rate. The greater adsorption (Kf) on the Palouse soil, for a given equilibration period, was attributed to the greater organic matter content. The continued trend of increase in apparent Kfwith time was due to degradation of methazole in solution to 3-(3,4-dichlorophenyl)-1-methylurea (DCPMU), which was highly adsorbed, rather than to increased adsorption of the parent compound. The calculated adsorption coefficients expressed in terms of soil organic carbon would classify methazole and DCPMU as immobile in Palouse soil and methazole as slightly mobile in Dundee soil. Calculated desorption isotherms, which exhibited a hysteretic effect, were also dependent on the rate of methazole degradation. The adsorption, desorption, and degradation data indicate that methazole would not leach readily in most soils.


1973 ◽  
Vol 53 (3) ◽  
pp. 307-314 ◽  
Author(s):  
R. GROVER

The movement of picloram (4-amino-3,5,6-trichloropicolinic acid) was studied in various Canadian Prairie soils, using soil columns. Picloram was readily leached in all soil types. The movement was greatest in the soil with the lowest organic matter and clay contents, and lowest in black soils that are high in soil organic matter content. It was related, in general, to the adsorptive and water-holding capacities of these soils. The extent of leaching of picloram was also related to the total amount of water applied; the greater the amount o¡ water the greater the downward movement. Increasing the intensity of water increments from 0.25 to 2.5 cm enhanced the movement of picloram in the clay soil but had no effect in the sandy loam. There was little or no difference in the movement of picloram when the herbicide was applied at 2.0 or 0.2 kg/ha, Picloram leached to a greater depth when the sandy loam soil was initially dry than wet and the converse was true for the clay soil. Picloram moved readily upwards when the soil columns were subirrigated.


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