Adsorption, Desorption, and Leaching of Diphenamid in Soils

Weed Science ◽  
1971 ◽  
Vol 19 (1) ◽  
pp. 67-69 ◽  
Author(s):  
J. Deli ◽  
G. F. Warren
Keyword(s):  
Organic Matter ◽  
Organic Matter Content ◽  
Fine Sand ◽  
Matter Content ◽  
Silt Loam ◽  
Muck Soil ◽  
Soil Mixtures ◽  
Adsorption Desorption

Leaching ofN,N-dimethyl-2,2-diphenylacetamide (diphenamid) was measured with bioassays in three soils; a fine sand, a silt loam, and a muck. The movement of diphenamid was reduced as the clay or the organic matter content of these soils increased. Efficiency of organic matter for adsorption of diphenamid decreased as the organic matter content of soil mixtures increased. Clay (bentonite) was less efficient than organic matter in adsorbing diphenamid. Desorption of diphenamid from muck soil was very slow.

Methazole Adsorption-Desorption in Soil

Weed Science ◽  
1984 ◽  
Vol 32 (2) ◽  
pp. 273-278 ◽  
Author(s):  
William C. Koskinen
Keyword(s):  
Organic Matter ◽  
Parent Compound ◽  
Organic Matter Content ◽  
Matter Content ◽  
Silt Loam ◽  
Degradation Data ◽  
Hysteretic Effect ◽  
Freundlich Adsorption Isotherm ◽  
Adsorption Desorption ◽  
Apparent Equilibrium

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.

Behavior and Fate of Metribuzin in Eight Ontario Soils

Weed Science ◽  
1976 ◽  
Vol 24 (2) ◽  
pp. 153-160 ◽  
Author(s):  
M. S. Sharom ◽  
G. R. Stephenson
Keyword(s):  
Organic Matter ◽  
Sandy Loam ◽  
Organic Matter Content ◽  
Distribution Coefficients ◽  
Matter Content ◽  
Soil Persistence ◽  
Muck Soil ◽  
Loam Soil ◽  
Mineral Soils ◽  
Adsorption Desorption

The adsorption, desorption, and mobility of metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazine-5(4H)one] in eight Ontario soils were investigated. The distribution coefficients varied from 0.56 for the least adsorptive Fox sandy loam soil to 31.67 for the most highly adsorptive Leamington muck soil. Most of the adsorbed metribuzin was desorbed from the mineral soils after six aqueous extractions, however substantial amounts of the herbicide remained adsorbed on the muck soils after 10 aqueous extractions. The herbicide was relatively mobile in mineral soils but was immobile in the muck soils. Mobility was inversely correlated with the amount of soil organic matter. Bioassay studies indicated that phytotoxicity of metribuzin also decreased with increasing organic matter content of the soil. Persistence of metribuzin was dependent on microbial degradation. In a field study with Guelph loam, the half-life of metribuzin was approximately 3 months.

Adsorption, Desorption, and Leaching of Nitrofen and Oxyfluorfen

Weed Science ◽  
1977 ◽  
Vol 25 (2) ◽  
pp. 97-100 ◽  
Author(s):  
Omosuyi Fadayomi ◽  
G. F. Warren
Keyword(s):  
Aqueous Solution ◽  
Calcium Ions ◽  
Fine Sand ◽  
Silica Sand ◽  
Distilled Water ◽  
Silt Loam ◽  
Sand Soil ◽  
Muck Soil ◽  
Loam Soil ◽  
Adsorption Desorption

The adsorption of nitrofen (2,4-dichlorophenyl-p-nitrophenyl ether) and oxyfluorfen [2-cholor-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene] from aqueous solution by muck soil, and by kaolinite and bentonite saturated with hydrogen or calcium ions, was studied using14C-labeled herbicides. Both compounds were readily adsorbed from solution by muck soil and Ca- and H-Al-bentonite but only slightly by Ca- and H-Al-kaolinite. Very little of the adsorbed compounds was desorbed after four extractions with distilled water. A bioactivity study using sorghum seedlings (Sorghum bicolorL. ‘RS610′) was conducted with the herbicides in a silica sand medium amended with 1% (w/w) of the various adsorbents. The herbicides were strongly inactivated by muck soil but there was very little inactivation by the clays. There was essentially no movement of either herbicide through 5-cm columns of a silt loam soil and a fine sand soil.

scholarly journals Diversity and distribution of crustaceans from 13 sheltered sandy beaches along São Sebastião Channel, south-eastern Brazil

2001 ◽  
Vol 81 (3) ◽  
pp. 475-484 ◽  
Author(s):  
P.R. Nucci ◽  
A. Turra ◽  
E.H. Morgado
Keyword(s):  
Organic Matter ◽  
Organic Matter Content ◽  
Clay Content ◽  
Fine Sand ◽  
Sandy Beaches ◽  
Matter Content ◽  
Sediment Grain Size ◽  
Crustacean Species ◽  
South Eastern ◽  
Eastern Brazil

The crustacean species composition in the intertidal zones of 13 sheltered unconsolidated marine beaches in south-eastern Brazil is described. Fifty-three crustacean species were collected, adding 46 species to the total reported by previous studies in the same region. Decapods dominated the community, in contrast to exposed sandy beaches where peracarids normally predominate. The species were distributed irregularly among the beaches. Richness varied markedly among sites, and was positively related to a combination of factors such as fine sand grains, high organic matter content, and relatively low silt–clay content. The presence of rock fragments enabled both rocky shore and sandy beach crustaceans to occur on the same beaches. Richness and abundance of crustaceans showed no clear relationship to sediment grain size and slope, in contrast to the norm for exposed sandy beaches. The dominance of the tanaid Kalliapseudes schubarti in some areas may be a result of organic matter pollution in the region. These beaches showed higher species richness than typical sheltered and exposed sandy beaches, indicating that this sheltered, highly heterogeneous seascape is an important area for conservation.

The influence of surfactant and organic matter content on wetting pattern of different non-water repellent soils

Soil Research ◽  
2016 ◽  
Vol 54 (7) ◽  
pp. 880
Author(s):  
Mohammad Reza Chaichi ◽  
Marcus Turcios ◽  
Mina Rostamza
Keyword(s):  
Organic Matter ◽  
Sandy Loam ◽  
Organic Matter Content ◽  
Matter Content ◽  
Water Infiltration ◽  
Water Repellent ◽  
Ionic Surfactant ◽  
Silt Loam ◽  
Wetted Area ◽  
Wetting Pattern

Non-ionic surfactants have been well researched as a tool to ameliorate water repellent conditions. However, few studies have evaluated the risks and benefits of non-ionic surfactant applications in wettable soil. The objective of this study was to evaluate the effects of a surfactant in modifying the wetting pattern in soils of different textures and organic matter contents. The experimental treatments consisted of (1) four different soil textures including sandy, sandy loam, sandy clay loam and silt loam, (2) four different organic matter contents (0.2, 0.7, 1.2 and 1.7% by weight), and (3) irrigation water treatments with or without surfactant (IrrigAid Gold). The experiment was carried out in Plexiglas boxes with one drip emitter under the soil surface. The results demonstrated the superiority of surfactant application on increasing water distribution in the soil profile for all soil textural classes. Silt loam texture had the highest side wetted area and wetting depth 45min after the initiation of irrigation. Upward capillary water movement and top wetted area significantly decreased in the surfactant treatment across all soil textures except in sandy soil. As organic matter content increased, top wetted area decreased. These findings clarified the potential ability of surfactant in increasing water infiltration in non-repellent soil in an in vitro system.

scholarly journals Superficial sediments and their relation to polyehaete families in a subtropieal embayment, Mexico

2015 ◽  
pp. 237-238
Author(s):  
Nuria Méndez ◽  
María Green Ruiz
Keyword(s):  
Grain Size ◽  
Organic Matter ◽  
Organic Matter Content ◽  
Fine Sand ◽  
Matter Content ◽  
Pearson’S Correlation ◽  
Pearson's Correlation ◽  
Superficial Sediments ◽  
Soft Bottoms

The soft bottoms in front of Mazatlan Bay and "Isla de la Piedra" Peninsula were studied to produce maps (depth, grain size and organic matter content in sediments). Sixty samples were óbtained with a 30 x 30 van Veen grab (4-21 m depth) and polychaetes were extracted from 21 subsamples. Grain size ranged from -1.05 phi (gravel) to 3 .81 phi (very fine sand), with fme sand predominl\ting. Organic matter content in sediment was 0.91-3.06 % (most values = 1-2 %). Thirty polychaete families (905 individuals/m2 in mean) were found, and Cirratulidae, Spionidae, Onuphidae, and Pilargiidae were domiuant. Pearson's correlation of grain size.

Napropamide Adsorption, Desorption, and Movement in Soils

Weed Science ◽  
1975 ◽  
Vol 23 (6) ◽  
pp. 454-457 ◽  
Author(s):  
Chu-Huang Wu ◽  
Normie Buehring ◽  
J. M. Davidson ◽  
P. W. Santelmann
Keyword(s):  
Sandy Loam ◽  
Organic Matter Content ◽  
Matter Content ◽  
Water Application ◽  
Soil Columns ◽  
Carbon 14 ◽  
Muck Soil ◽  
Loam Soil ◽  
Adsorption Desorption ◽  
Layer Chromatography

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.

Sign in / Sign up

Export Citation Format

Share Document