Solute movement through two unsaturated soils

Soil Research ◽  
1995 ◽  
Vol 33 (4) ◽  
pp. 585 ◽  
Author(s):  
GN Magesan ◽  
I Vogeler ◽  
DR Scotter ◽  
BE Clothier ◽  
RW Tillman
Keyword(s):  
Unsaturated Soils ◽  
Sandy Loam ◽  
Breakthrough Curves ◽  
Dead Volume ◽  
Silt Loam ◽  
Soil Columns ◽  
Concentration Data ◽  
Fine Sandy Loam ◽  
Solute Movement ◽  
Structured Soil

Simple and inexpensive apparatus is described for studying the solute movement during unsaturated water flow through intact soil columns. A preset pressure head is maintained at the top and bottom of the soil. The applied solution is easily changed, and there is negligible 'dead volume' both above and beneath the soil. Columns 37-150 mm long, carved from the A horizons of a well structured silt loam and a weakly structured fine sandy loam, were used in the apparatus. After the soil was preleached with calcium sulfate solution, solid potassium nitrate was applied, followed by a solution of potassium chloride. Nitrate and chloride concentrations in the effluent, and in the soil after leaching, were measured. With the imposed pressure heads of between -40 and -150 mm, flow rates ranged from 0 . 5 to 9 mm/h. The convection dispersion equation (CDE) with the appropriate boundary conditions was found to adequately describe the flow of chloride and nitrate in both soils. The outflow concentration data indicated all the soil water participated in the solute transport, and the chloride breakthrough curves scaled with column length as predicted by the CDE rather than by stochastic-convective theory. The dispersivity values for the well structured silt loam were 15 and 19 mm. The values for the weakly structured fine sandy loam were 68 and 27 mm. The dispersivity may be a useful structure index, as well as being the key parameter needed to describe solute movement. The resident concentration data indicated all the water in the well structured soil was mobile, but about 15% of the water in the weakly structured soil was relatively immobile.

Chloride and Lithium Transport in Large Arrays of Undisturbed Silt Loam and Sandy Loam Soil Columns

2004 ◽  
Vol 3 (1) ◽  
pp. 316
Author(s):  
M. Saleem Akhtar ◽  
Tammo S. Steenhuis ◽  
Brian K. Richards ◽  
Murray B. McBride
Keyword(s):  
Sandy Loam ◽  
Sandy Loam Soil ◽  
Silt Loam ◽  
Soil Columns ◽  
Lithium Transport ◽  
Loam Soil

Mobility of Herbicides in Soil Columns Under Saturated- and Unsaturated-Flow Conditions

Weed Science ◽  
1982 ◽  
Vol 30 (6) ◽  
pp. 579-584 ◽  
Author(s):  
Jerome B. Weber ◽  
David M. Whitacre
Keyword(s):  
Unsaturated Flow ◽  
Sandy Loam ◽  
High Water ◽  
Loamy Sand ◽  
Silt Loam ◽  
Flow Conditions ◽  
Soil Columns ◽  
Saturated Flow

Under unsaturated-flow conditions, bromacil (5-bromo-3-sec-butyl-6-methyluracil) was considerably more mobile than buthidazole {3-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-4-hydroxyl-1-methyl-2-imidazolidinone}. Because of their high water solubilities, both herbicides were much more mobile than atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine), prometon [2,4-bis (isopropylamino)-6-methoxy-s-triazine], or diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea]. Under saturated-flow conditions, buthidazole was leached through Lakeland loamy sand in slightly greater amounts than tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethylurea} or CN-10-3510 (formerly VEL 3510) {1-β,β-dimethoxyl-1-methyl-3-[5-(1,1-dimethylethyl)-1,3, 4-thiadiazol-2-yl] urea}. Distribution of the three herbicides in the leached soil was similar and relatively uniform. In Lakeland loamy sand, 30 times as much tebuthiuron was leached under saturated-flow conditions as under unsaturated-flow conditions. Intermittent saturated-unsaturated-flow conditions resulted in four times as much leaching of tebuthiuron as unsaturated flow alone. Only one-tenth as much tebuthiuron leached under intermittent saturated-unsaturated-flow conditions as under saturated-flow conditions. Tebuthiuron added to Lakeland soil and oven-dried was retained in significantly greater amounts than when added to moist Lakeland soil. Low amounts of tebuthiuron leached through Lakeland loamy sand, Portsmouth sandy loam, and Rains silt loam, but high amounts leached through Davidson clay. Greater amounts of the herbicide were retained in the surface zones of the three former soils, but the inverse was the case for the Davidson soil.

Distribution of Arsenic in Soil Profiles after Repeated Applications of MSMA

Weed Science ◽  
1974 ◽  
Vol 22 (3) ◽  
pp. 272-275 ◽  
Author(s):  
A. E. Hiltbold ◽  
B. F. Hajek ◽  
G. A. Buchanan
Keyword(s):  
Sandy Loam ◽  
Soil Column ◽  
Loamy Sand ◽  
Soil Types ◽  
Soil Profiles ◽  
Silt Loam ◽  
Column Studies ◽  
Fine Sandy Loam ◽  
Surface Horizon ◽  
Repeated Applications

Arsenic as MSMA (monosodium methanearsonate) was applied to three soil types over a 6-year period. Percentage recovery of applied arsenic averaged 67, 57, and 39% in Hart-sells fine sandy loam, Decatur silt loam, and Dothan loamy sand soils, respectively. Essentially all of the arsenic recovered in the soils occurred in the plow layer with no evidence of leaching into deeper zones. Batch-equilibrium and soil-column studies in the laboratory indicated that the rate of MSMA movement through the surface horizon would be fastest in Dothan loamy sand and slowest in Decatur silt loam.

Influence of Acetamide Herbicide Applications on Efficacy of the Protectant CGA-43089 in Grain Sorghum (Sorghum bicolor)

Weed Science ◽  
1980 ◽  
Vol 28 (6) ◽  
pp. 646-649 ◽  
Author(s):  
G. S. Simkins ◽  
L. J. Moshier ◽  
O. G. Russ
Keyword(s):  
Sorghum Bicolor ◽  
Plant Height ◽  
Seed Treatment ◽  
Sandy Loam ◽  
Grain Sorghum ◽  
Plant Population ◽  
Field Conditions ◽  
Silt Loam ◽  
Fine Sandy Loam

The influence of acetamide herbicide applications on efficacy of CGA-43089 [α-(cyanomethoximino)-benzacetonitrile] in grain sorghum [Sorghum bicolor(L.) Moench] was studied under field conditions. Acetamide herbicides applied preplant and incorporated on a Haynie very fine sandy loam caused more grain sorghum injury in 1979 than in 1978. Reductions in plant population, plant height and yield, along with delay in maturity, were severe for acetochlor [2-chloro-N-(ethoxymethyl)-6′-ethyl-O-acetotoluidide], metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide], and alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide]; moderate for diethatyl [N-(chloroacetyl)-N-(2,6-diethylphenyl)glycine], xylachlor [2-chloro-N-(2,3-dimethylphenyl)-N-(1-methylethyl)acetamide], and butam [2,2-dimethyl-N-(1-methylethyl)-N-(phenylmethyl)propanamide]; and did not occur for propachlor (2-chloro-N-isopropylacetanilide) treatments. Acetamide herbicides caused less grain sorghum injury on a Reading silt loam than on a Haynie very fine sandy loam in 1979. CGA-43089 applied as a seed treatment protected grain sorghum grown on soils treated with metolachlor, alachlor, diethatyl, or xylachlor. Metolachlor-triazine combinations at five locations in Kansas reduced yields at two locations. CGA-43089 provided protection from metolachlor injury at those two locations.

Chloride and Lithium Transport in Large Arrays of Undisturbed Silt Loam and Sandy Loam Soil Columns

2004 ◽  
Vol 3 (1) ◽  
pp. 316-316
Author(s):  
M. Saleem Akhtar ◽  
Tammo S. Steenhuis ◽  
Brian K. Richards ◽  
Murray B. McBride
Keyword(s):  
Sandy Loam ◽  
Sandy Loam Soil ◽  
Silt Loam ◽  
Soil Columns ◽  
Lithium Transport ◽  
Loam Soil

Sorption and Mobility of Chlorimuron in Alabama Soils

Weed Science ◽  
1989 ◽  
Vol 37 (3) ◽  
pp. 428-433 ◽  
Author(s):  
Andrew J. Goetz ◽  
Robert H. Walker ◽  
Glenn Wehtje ◽  
Ben F. Hajek
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Soil Ph ◽  
Soil Type ◽  
Sandy Loam ◽  
Solution Technique ◽  
Silt Loam ◽  
Fine Sandy Loam ◽  
Highly Correlated ◽  
Layer Chromatography

Soil thin-layer chromatography and a soil solution technique were used to evaluate chlorimuron adsorption and mobility in five Alabama soils. The order of adsorption was atrazine > metribuzin > chlorimuron; mobility was chlorimuron > metribuzin > atrazine. The order of adsorption of chlorimuron in the five soils was Sumter clay > Eutaw clay > Lucedale fine sandy loam > Decatur silt loam > Dothan sandy loam, and Rfvalues were 0.63, 0.73, 0.69, 0.76, and 0.80, respectively. Chlorimuron mobility and adsorption were not highly correlated to any one soil type. Adsorption of all herbicides was inversely related to soil pH. Maximum chlorimuron adsorption in the Hiwassee loam was attributed to the high hematite and gibbsite content of the soil.

scholarly journals Biochar alters hydraulic conductivity and inhibits nutrient leaching in two agricultural soils

2021 ◽  
Author(s):  
Danielle L. Gelardi ◽  
Irfan Ainuddin ◽  
Devin A. Rippner ◽  
Majdi Abou Najm ◽  
Sanjai J. Parikh
Keyword(s):  
Hydraulic Conductivity ◽  
Sandy Loam ◽  
High Surface ◽  
High Surface Area ◽  
Nutrient Retention ◽  
Breakthrough Curves ◽  
Nutrient Leaching ◽  
Silt Loam ◽  
Primary Control ◽  
Almond Shell

Abstract. Biochar is purported to provide agricultural benefits when added to the soil, through changes in soil water hydraulic conductivity (Ksat), and increased nutrient retention through chemical or physical means. Despite increased interest and investigation, there remains uncertainty regarding the ability of biochar to deliver these agronomic benefits due to differences in biochar feedstock, production method, production temperature and soil texture. In this project, a suite of experiments was carried out using biochars of diverse feedstocks and production temperatures, in order to determine the biochar parameters which may optimize agricultural benefits. Sorption experiments were performed with seven distinct biochars to determine sorption efficiencies for ammonium and nitrate. Only one biochar effectively retained nitrate, while all biochars bound ammonium. The three biochars with the highest binding capacities (produced from almond shell at 500 and 800 °C (AS500 and AS800) and softwood at 500 °C (SW500)) were chosen for column experiments. Biochars were amended to a sandy loam and a silt loam at 0 and 2 % (w/w) and saturated hydraulic conductivity (Ksat) was measured. Biochars reduced Ksat in both soils by 64–80 %, with the exception of AS800, which increased Ksat by 98 % in the silt loam. Breakthrough curves for nitrate and ammonium, as well as leachate nutrient concentration, were also measured in the sandy loam columns. All biochars significantly decreased the quantity of ammonium in the leachate, by 22 to 78 %, and slowed its movement through the soil profile. Ammonium retention was linked to high cation exchange capacity and a high oxygen to carbon ratio, indicating that the primary control of ammonium retention in biochar-amended soils is the chemical affinity between biochar surfaces and ammonium. Biochars had little to no effect on the timing of nitrate release, and only SW500 decreased total quantity, by 27 to 36 %. The ability of biochar to retain nitrate may be linked to high surface area, suggesting a physical entrapment rather than a chemical binding. Together, this work sheds new light on the combined chemical and physical means by which biochar may alter soils to impact nutrient leaching and hydraulic conductivity for agricultural production.

Analysis of partial breakthrough data by a transfer-function method

Soil Research ◽  
2006 ◽  
Vol 44 (2) ◽  
pp. 175 ◽  
Author(s):  
M. A. Mojid ◽  
D. A. Rose ◽  
G. C. L. Wyseure
Keyword(s):  
Transfer Function ◽  
Solute Transport ◽  
Calcium Chloride ◽  
Unsaturated Soils ◽  
Function Method ◽  
Sandy Loam ◽  
Breakthrough Curves ◽  
Time Domain Reflectometry ◽  
Transport Parameters ◽  
Transfer Function Method

A transfer-function method has been applied to determine solute-transport parameters from earlier sections of complete breakthrough data. Time-domain reflectometry allows the measurement of breakthrough data in unsaturated soil. In fine-textured soils, the flow of water must be kept low to maintain unsaturated conditions, and so experiments for a complete breakthrough of solute may last a very long time. Substantial savings of time and computer memory might be achieved if data could be analysed from an earlier section of breakthrough data. Data at 2 vertical positions (input at upper and response at lower position) from a complete breakthrough of calcium chloride applied as a pulse input to 4 unsaturated soils (coarse sand, sandy loam, clay loam, clay) were divided into 4 sets of increasing duration. Transport parameters of calcium chloride were determined by a transfer function, which results in similar values of the parameters from the last 3 datasets in all 4 soils. In the clay soil, however, because of erroneous breakthrough data the fit between the measured and estimated breakthrough curves (BTCs) was poor, but the transport parameters were consistent among different segments of data. We show that it is possible to determine successfully solute-transport parameters from partial breakthrough data, which include the peak of the response BTC. This transfer-function method is thus a powerful tool to shorten breakthrough experiments.

Influence of soil structure on sulfate leaching from a silt loam

Soil Research ◽  
1992 ◽  
Vol 30 (4) ◽  
pp. 443 ◽  
Author(s):  
CDA Mclay ◽  
KC Cameron ◽  
RG Mclaren
Keyword(s):  
Soil Structure ◽  
Packed Column ◽  
Breakthrough Curves ◽  
Natural Soil ◽  
Silt Loam ◽  
Soil Columns ◽  
Undisturbed Soil ◽  
Soil Monolith ◽  
Sulfate Leaching ◽  
Soil Lysimeters

The influence of soil structure on sulfate leaching from a silt loam soil was assessed by comparing the results of leaching experiments conducted using undisturbed soil monolith lysimeters and re-packed soil columns. A pulse application of sulfate solution was leached through both soil systems under non-ponded infiltration conditions. Breakthrough curves (BTCs) from the undisturbed soil lysimeters were poly-modal compared with the uni-modal curves observed in re-packed column experiments. The poly-modal BTC is considered to result from sulfate leached through isolated porosity regions within the undisturbed soil monolith. Sulfate leaching rates were faster through the undisturbed soil lysimeters and this was attributed to solute transport through the natural soil macropore system, which is retained in the undisturbed soil but lost in the repacked soil columns. Leaching through soil macropores therefore can result in considerable losses of sulfur from silt loam textured soils.

scholarly journals Biochar alters hydraulic conductivity and impacts nutrient leaching in two agricultural soils

SOIL ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 811-825
Author(s):  
Danielle L. Gelardi ◽  
Irfan H. Ainuddin ◽  
Devin A. Rippner ◽  
Janis E. Patiño ◽  
Majdi Abou Najm ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Agricultural Soils ◽  
Sandy Loam ◽  
Nutrient Retention ◽  
Production Method ◽  
Breakthrough Curves ◽  
Nutrient Leaching ◽  
Silt Loam ◽  
Primary Control ◽  
Almond Shell

Abstract. Biochar is purported to provide agricultural benefits when added to the soil, through changes in saturated hydraulic conductivity (Ksat) and increased nutrient retention through chemical or physical means. Despite increased interest and investigation, there remains uncertainty regarding the ability of biochar to deliver these agronomic benefits due to differences in biochar feedstock, production method, production temperature, and soil texture. In this project, a suite of experiments was carried out using biochars of diverse feedstocks and production temperatures, in order to determine the biochar parameters which may optimize agricultural benefits. Sorption experiments were performed with seven distinct biochars to determine sorption efficiencies for ammonium and nitrate. Only one biochar effectively retained nitrate, while all biochars bound ammonium. The three biochars with the highest binding capacities (produced from almond shell at 500 and 800 ∘C (AS500 and AS800) and softwood at 500 ∘C (SW500)) were chosen for column experiments. Biochars were amended to a sandy loam and a silt loam at 0 % and 2 % (w/w), and Ksat was measured. Biochars reduced Ksat in both soils by 64 %–80 %, with the exception of AS800, which increased Ksat by 98 % in the silt loam. Breakthrough curves for nitrate and ammonium, as well as leachate nutrient concentration, were also measured in the sandy loam columns. All biochars significantly decreased the quantity of ammonium in the leachate, by 22 % to 78 %, and slowed its movement through the soil profile. Ammonium retention was linked to high cation exchange capacity and a high oxygen-to-carbon ratio, indicating that the primary control of ammonium retention in biochar-amended soils is the chemical affinity between biochar surfaces and ammonium. Biochars had little to no effect on the timing of nitrate release, and only SW500 decreased total quantity, by 27 % to 36 %. The ability of biochar to retain nitrate may be linked to high micropore specific surface area, suggesting a physical entrapment rather than a chemical binding. Together, this work sheds new light on the combined chemical and physical means by which biochar may alter soils to impact nutrient leaching and hydraulic conductivity for agricultural production.

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