Atrazine Degradation in Two Soil Profiles

Weed Science ◽  
1969 ◽  
Vol 17 (2) ◽  
pp. 202-205 ◽  
Author(s):  
F. W. Roeth ◽  
T. L. Lavy ◽  
O. C. Burnside
Keyword(s):  
Degradation Rate ◽  
Field Capacity ◽  
Solution Culture ◽  
Side Chain ◽  
Soil Profiles ◽  
Silty Clay ◽  
Silt Loam ◽  
Clay Loam ◽  
Silty Clay Loam ◽  
Culture Studies

Degradation of 2-chloro-4-ethylamino-6-isopropyl-s-triazine (atrazine) was studied in the 0 to 9, 14 to 24, and 36 to 48-inch depths of Sharpsburg silty clay loam and Keith silt loam soils. The effects of moisture, temperature, and microorganisms on degradation were observed. Atrazine was degraded two to three times faster in the topsoils than in the subsoils. Each 10 C temperature increase from 15 to 35 C caused the degradation rate to increase two to three times in these soils. Increasing the moisture content of the soils from 0.4 to 0.8 field capacity caused 14CO2 evolution from chain-labeled atrazine-14C treated soils to increase zero to six times. At 25 C and 0.8 field capacity, 100 to 194 atrazine molecules were detoxified for each molecule evolved as 14CO2 from chain-labeled atrazine. Solution culture studies showed cleavage of the side chain and ring of atrazine-14C except in the 14 to 24 and 36 to 48-inch depths of Keith silt loam.

Influence of Various Soil Properties on the Adsorption and Desorption of ICIA-0051 in Five Soils

1992 ◽  
Vol 6 (3) ◽  
pp. 583-586 ◽  
Author(s):  
John S. Wilson ◽  
Chester L. Foy
Keyword(s):  
Sandy Loam ◽  
Clay Content ◽  
Silty Clay ◽  
Silt Loam ◽  
Clay Loam ◽  
Soil Factors ◽  
Silty Clay Loam ◽  
Freundlich Equation ◽  
General Order ◽  
Highly Correlated

The soil organic matter and/or humic matter fraction was highly correlated with the adsorption of ICIA-0051 herbicide onto five soils; clay content and other soil factors were less correlated. The Freundlich equation was used to describe the adsorption of ICIA-0051 by the various soils. Based on the K constants, the general order for adsorption for each soil was Hyde silty clay loam > Frederick silt loam > Davidson clay = Bojac sandy loam > Appling loamy sand. Across all soils, 25 to 50% of the amount adsorbed was removed by two desorptions. Appling, Bojac, and Davidson soils retained less herbicide after two desorptions than did Frederick and Hyde.

Effect of Soil pH on Degradation, Movement, and Plant Uptake of Chlorsulfuron

Weed Science ◽  
1986 ◽  
Vol 34 (2) ◽  
pp. 328-332 ◽  
Author(s):  
David R. Fredrickson ◽  
Patrick J. Shea
Keyword(s):  
Soil Ph ◽  
Plant Uptake ◽  
Degradation Rate ◽  
Silty Clay ◽  
Clay Loam ◽  
Silty Clay Loam ◽  
Leaching Potential ◽  
Incubation Study ◽  
Ph Range ◽  
Layer Chromatography

The influence of soil pH on the uptake, degradation, and movement of chlorsulfuron {2-chloro-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino] carbonyl] benzenesulfonamide} in soil was examined. Phytotoxicity decreased as pH increased in a silty clay loam with an adjusted pH range of 5.9 to 7.5. Fresh weights of sorghum [Sorghum bicolor(L.) Moench. ‘Funks G-499 GBR’] shoots grown in soil at pH 7.5 and containing 0.8 or 1.6 ppbw chlorsulfuron were not different from the controls while large differences occurred at pH 5.9. Uptake of14C-chlorsulfuron by wheat (Triticum aestivumL. ‘Centurk’) in a silty clay loam with a pH of 5.9 was 67 to 100% greater than at pH 7.5. Soil pH strongly influenced the degradation rate of chlorsulfuron in a laboratory incubation study. Chlorsulfuron half-life in a silty clay loam was 1.9 weeks at pH 5.6 and 10 weeks at pH 7.5. Soil thin-layer chromatography indicated a high leaching potential for chlorsulfuron, and mobility increased as soil pH was increased.

Simulating the vertical transition of soil textural layers in north-western China with a Markov chain model

Soil Research ◽  
2013 ◽  
Vol 51 (3) ◽  
pp. 182 ◽  
Author(s):  
Danfeng Li ◽  
Ming'an Shao
Keyword(s):  
Layer Thickness ◽  
Sandy Loam ◽  
Loamy Sand ◽  
Silty Clay ◽  
Silt Loam ◽  
Clay Loam ◽  
Silty Clay Loam ◽  
Textural Type ◽  
Log Normal ◽  
Log Normal Distribution

The heterogeneity of textures in soil profiles is important for quantifying the movement of water and solutes through soil. Soil-profile textures to a depth of 300 cm were investigated at 100 sites in a 100-km2 area in the central region of the Heihe River system, where oases coexist with widespread deserts and wetland. The probability distribution of textural-layer thickness was quantified. The vertical transition of the soil textural layers was characterised by a Markov chain–log-normal distribution (MC-LN) model based on the probability of one textural type transitioning to another. Nine types of textural layers were observed: sand, loamy sand, sandy loam, silt loam, loam, clay loam, silty clay loam, silty clay, and clay. Sand was the most frequent in the profiles, whereas silt loam and clay were rare. The layers of sand and silty clay were relatively thick, and the layers of loam and clay were relatively thin. The coefficients of variation ranged from 36–87%, indicating moderate variation in the layer thickness of each textural type. The soil profile was characterised as a log-normal distribution. A χ2 test verified the Markov characteristic and the stability of the vertical change of soil textural layers. Realisations of the soil textural profiles were generated by the MC-LN model. A Monte Carlo simulation indicated that the simulated mean layer thickness of each textural type agreed well with the corresponding field observations. Element values of the transition probability matrix of the textural layers simulated by the MC-LN model deviated <12.6% from the measured values, excluding the data from the layers of clay and silt loam. The main combinations of upper to lower textural layers in the study area were loamy sand and sand (or sandy loam), sandy loam and sand (or loamy sand and loam), loam and clay loam, clay loam (or silty clay) and silty clay loam, and silty clay loam and silty clay. The MC-LN model was able to accurately quantify the vertical changes of textures in the soil profiles. This study will aid in quantification of water and solute transport in soils with vertical heterogeneity of soil textural layers.

Interaction of Metribuzin and Trifluralin with Soil Type on Soybean(Glycine max)Growth

Weed Science ◽  
1978 ◽  
Vol 26 (4) ◽  
pp. 327-331 ◽  
Author(s):  
R. S. Moomaw ◽  
A. R. Martin
Keyword(s):  
Glycine Max ◽  
Field Experiments ◽  
Growth And Yield ◽  
Silty Clay ◽  
Silt Loam ◽  
Clay Loam ◽  
Herbicide Application ◽  
Silty Clay Loam ◽  
Early Season ◽  
Soybean Yield

Field experiments were conducted on a Moody silty clay loam (pH 6.5) and a Crofton silt loam (pH 7.9) to evaluate the influence of soil texture and pH on metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one] toxicity to soybeans [Glycine max(L.) Merr. ‘Amsoy 71’] as influenced by trifluralin [α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine]. One Crofton silt loam site contained atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] residue. Soybean growth and yield was not significantly affected by metribuzin and trifluralin applications on the Moody silty clay loam. On the Crofton silt loam without atrazine residue, substantial early season soybean injury from metribuzin did not result in significantly reduced soybean yield. Atrazine residue from previous row banding on corn(Zea maysL.) on the Crofton silt loam reduced soybean tolerance to metribuzin but normal use rates of 0.4 kg/ha metribuzin did not significantly reduce soybean yield. Trifluralin reduced early season soybean injury from metribuzin but this effect was not reflected in soybean yield. Metribuzin injury to soybeans was greater in years when more rainfall and cooler temperatures occurred following herbicide application. Metribuzin applied either preplant incorporated with or as an overlay on trifluralin resulted in equal soybean injury and yield.

Availability and Persistence of Imazaquin, Imazethapyr, and Clomazone in Soil

Weed Science ◽  
1989 ◽  
Vol 37 (2) ◽  
pp. 259-267 ◽  
Author(s):  
Mark M. Loux ◽  
Rex A. Liebl ◽  
Fred W. Slife
Keyword(s):  
Organic Matter ◽  
Root Growth ◽  
Chromatographic Analysis ◽  
Shoot Growth ◽  
Field Experiments ◽  
Silty Clay ◽  
Silt Loam ◽  
Clay Loam ◽  
Silty Clay Loam ◽  
Crop Injury

The availability and persistence of imazaquin, imazethapyr, and clomazone were studied in a Cisne silt loam (1.3% organic matter) and a Drummer silty clay loam (5.8% organic matter). Availability of all three herbicides to bioassay species was greater in the Cisne soil than in the Drummer soil. Corn root growth was more sensitive to imazaquin and imazethapyr than corn shoot growth. Shoot and root growth of wheat was inhbited by similar clomazone concentrations. In field experiments conducted in 1984, 1985, and 1986, all three herbicides were more persistent in the Drummer silty clay loam than in the Cisne silt loam. Clomazone and imazethapyr were detected by liquid or gas chromatographic analysis in the Drummer soil 3 yr following application. Crop injury occurred 5 months after application of imazaquin and clomazone to the Drummer soil. In the Cisne soil, only imazethapyr caused crop injury 5 months after application. Herbicide residues found below 7.5 cm were greater in the Drummer soil than in the Cisne soil.

Biological and Non-Biological Dissipation of Trifluralin from Soil

Weed Science ◽  
1971 ◽  
Vol 19 (3) ◽  
pp. 285-290 ◽  
Author(s):  
C. G. Messersmith ◽  
O. C. Burnside ◽  
T. L. Lavy
Keyword(s):  
Sandy Loam ◽  
Field Capacity ◽  
Silty Clay ◽  
Clay Loam ◽  
Silty Clay Loam

Phytotoxicity of α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin), incubated for 10 months in Sharpsburg silty clay loam at 0.8 field capacity, remained a 6.4, 0, and 1.6 ppmw of the original 8 ppmw at 15, 25, and 35 C, respectively. In Anselmo sandy loam after 10-months incubation, trifluralin phytotoxicity remained at 3.0, 3.2, and 0.6 ppmw of the original 4 ppmw at 15, 25, and 35 C, respectively. Breakdown of 14C-trifluralin to 14CO2 in both soils was more rapid at 1.6 field capacity than at 0.8 field capacity, and at 1 ppmw than at 100 ppmw of trifluralin. Breakdown of 14C-trifluralin to 14CO2 accounted for 5 and 3% of the decrease of 14C-activity in Sharpsburg silty clay loam and Anselmo sandy loam, respectively.

Photolysis of Imidazolinone Herbicides in Aqueous Solution and on Soil

Weed Science ◽  
1992 ◽  
Vol 40 (1) ◽  
pp. 143-148 ◽  
Author(s):  
William S. Curran ◽  
Mark M. Loux ◽  
Rex A. Liebl ◽  
F. William Simmons
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Ultraviolet Light ◽  
Field Capacity ◽  
Silty Clay ◽  
Clay Loam ◽  
Silty Clay Loam ◽  
Moist Sand ◽  
Photolytic Degradation ◽  
Imidazolinone Herbicides

The photolytic degradation of several imidazolinone herbicides in solution and on soil was investigated. Ultraviolet light caused 100% degradation of imazaquin, imazethapyr, and imazapyr, and 87 and 8% degradation of imazamethabenz and atrazine in aqueous solutions, respectively, after 48 h. The order of susceptibility to photolysis in decreasing order was imazaquin = imazethapyr > imazapyr > imazamethabenz > atrazine. In soil Studies, 45% of imazaquin and 52% of imazethapyr dissipated from moist sand after 48 h of exposure. Herbicide dissipation on air-dry sand and on field capacity and air-dry silty clay loam was less than 10% in most instances. Atrazine photolysis was not detected. This research indicates that photolysis of imidazolinone herbicides in solution is rapid. Photolysis on soil occurs readily on coarse-textured wet soils probably due to greater availability of the herbicide for photochemical alteration.

Residual Phytotoxicity of Fluometuron in Soils

Weed Science ◽  
1968 ◽  
Vol 16 (2) ◽  
pp. 226-229 ◽  
Author(s):  
Roger L. Darding ◽  
J. F. Freeman
Keyword(s):  
Organic Matter ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Silty Clay ◽  
Silt Loam ◽  
Clay Loam ◽  
Silty Clay Loam ◽  
Greenhouse Condition ◽  
Exchangeable Bases ◽  
Soluble Phosphorus

Initial and residual phytotoxicity of 3-(m-trifluoromethylphenyl)-1, 1-dimethylurea (fluometuron) in seven soils was studied under greenhouse condition, using oats (Avena sativa L., var. Brave) as the bioassay species. The phytotoxicity of fluometuron in four of the soils, with an organic matter range of 1.0 to 5.0%, was not different at any one of the five cropping periods. Inactivation of fluometuron was more rapid in Eden silty clay loam with 3.3% organic matter than in Maury silty clay loam/silt loam with 7.2% organic matter. Phytotoxicity was significantly correlated with organic matter and soluble phosphorus during the first two cropping periods, and with cation exchange capacity, exchangeable calcium, total exchangeable bases, and soluble phosphorus during the last three croppings.

Influence of soil texture on snowmelt infiltration into frozen soils

2002 ◽  
Vol 82 (1) ◽  
pp. 75-83 ◽  
Author(s):  
Litong Zhao ◽  
D. M. Gray ◽  
B. Toth
Keyword(s):  
Soil Texture ◽  
Agricultural Soils ◽  
Sandy Loam ◽  
Phase Changes ◽  
Silty Clay ◽  
Silt Loam ◽  
Clay Loam ◽  
Silty Clay Loam ◽  
Infiltration Process ◽  
Frozen Soils

This paper describes the influence of soil texture on snowmelt infiltration into frozen soils. Field data collected on frozen, unsaturated agricultural soils of the Canadian Prairies during snow ablation demonstrate: (a) poor association between the amount of infiltration of meltwater released by the seasonal snowcover and soil texture, and (b) small differences in cumulative amounts among soils of widely different textures. A physics-based numerical simulation of heat and mass transfers with phase changes in frozen soils is used to study the mechanics of the infiltration process in representative clay, silty clay loam, silt loam and sandy loam soils. The results of the simulations show that the differences among cumulative snowmelt infiltration into clay, silty clay loam and silt loam soils after 24 h of continuous infiltration are small. Infiltration into a lighter-textured sandy loam after 24 h was on average 23% higher than in the other three soils with most of the increase occurring in the first 5 h of the simulation. Key Words: Soil texture, snowmelt, infiltration, frozen soils

Sulfentrazone sorption, desorption, and mineralization in soils from two tillage systems

Weed Science ◽  
1998 ◽  
Vol 46 (4) ◽  
pp. 494-500 ◽  
Author(s):  
Krishna N. Reddy ◽  
Martin A. Locke
Keyword(s):  
Sorption Kinetics ◽  
Microbial Populations ◽  
Plant Residues ◽  
Silty Clay ◽  
Silt Loam ◽  
Clay Loam ◽  
Silty Clay Loam ◽  
No Till ◽  
Loam Soil

Sulfentrazone sorption kinetics, desorption, and mineralization were evaluated in surface 7.5 cm of soils collected from long-term conventional-till (CT) and no-till (NT) plots. The soils used were Miami silt loam and Drummer silty clay loam from Illinois and Dundee silt loam from Mississippi. Sulfentrazone sorption kinetics in Dundee silt loam CT and NT soils were adequately described by a simple two-site equilibrium/kinetic model. Rapid initial sorption (within 1 h) was followed by a slower sorption and equilibrium, largely achieved by 72 h of shaking, with a negligible increase in sorption thereafter. The sorptionKfranged from 1.02 to 3.44 among the six CT and NT soils. TheKfvalues were greater for NT compared to their respective CT soils. Overall,Kfvalues were higher in Drummer silty clay loam followed by Dundee silt loam and Miami silt loam soil. TheNvalues were less than unity in all soils indicating nonlinear sorption. Sulfentrazone desorption was hysteretic with a very low rate of desorption. The total amount desorbed in four desorptions ranged from 58 to 72% of that sorbed. Less than 2.1% of applied14C-sulfentrazone was mineralized to14CO2 in Dundee silt loam CT and NT soils during a 77–d incubation. Relatively low mineralization of sulfentrazone suggests poor adaptability of native microbial populations that have not been exposed to this herbicide. Higher sorption and lower desorption of sulfentrazone in NT soils compared to CT soils suggest that NT systems (which tend to increase plant residues) may prolong sulfentrazone residence time in soil.

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