Nitrate Mobility Under Unsaturated Flow Conditions in Four Initially Dry Soils

Allred, Barry J.; Brown, Glenn O.; Bigham, Jerry M.

doi:10.1097/01.ss.0000240548.44551.74

Cited by 17 publications

(11 citation statements)

References 30 publications

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“…Second, similarity of the NO 3 − –N concentration profiles implies that, for a particular soil, chemical interactions involving NO 3 − were reversible, with equilibrium conditions rapidly reached. Third, as discussed by Allred et al (2007), NO 3 − –N concentration profile similarity additionally indicates that the following concentration ( C ) boundary conditions existed for the tests conducted in this study:

\begin{matrix} C = C_{0}, for λ = 0 (x = 0 and t > 0) \end{matrix}

The boundary condition given by Eq. [11] states that the NO 3 − –N inlet concentration is kept constant throughout the test.…”

Section: Resultsmentioning

confidence: 54%

“…Most important, the results show anion exclusion to be an important process affecting NO 3 − mobility not only in some artificial sand–clay mixtures but also in natural soils that commonly contain a variety of clay minerals. (Comparison of some of the test results obtained by Allred et al [2007] with the test results acquired in this study with the Slaughterville and Teller soils indicates that for these two natural soils, neither organic matter removal by hydrogen peroxide oxidation nor oven drying the soil at 100°C alters clay mineralogy or soil physicochemical properties to the extent that it affects water or NO 3 − movement. )…”

Section: Resultsmentioning

confidence: 56%

“…Research at a larger scale with 6‐m‐long vertical soil columns and at field test plots confirmed that anion exclusion impacts the mobility of Cl − , Br − , and even sulfate (Gvirtzman et al, 1986; Hills et al, 1991; Porro and Wierenga, 1993; Porro et al, 1993). Allred et al (2007) determined anion exclusion to be the dominant electrostatic process affecting NO 3 − transport under unsaturated flow conditions in four initially dry soils having widely different physicochemical and mineralogical properties. Additionally, Allred et al (2007) found that for three of the four initially dry soils evaluated using transient unsaturated column tests, the wetting front NO 3 − concentration was significantly greater than the NO 3 − concentration of the solution injected at the column inlet.…”

mentioning

confidence: 99%

“…Allred et al (2007) determined anion exclusion to be the dominant electrostatic process affecting NO 3 − transport under unsaturated flow conditions in four initially dry soils having widely different physicochemical and mineralogical properties. Additionally, Allred et al (2007) found that for three of the four initially dry soils evaluated using transient unsaturated column tests, the wetting front NO 3 − concentration was significantly greater than the NO 3 − concentration of the solution injected at the column inlet.…”

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confidence: 99%

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The Impact of Clay Mineralogy on Nitrate Mobility under Unsaturated Flow Conditions

Allred¹,

Bigham

Brown

2007

Vadose Zone Journal

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Transient unsaturated horizontal column experiments were conducted to assess clay mineralogy impacts on electrostatic processes affecting nitrate (NO3−) mobility. Replicated tests were conducted on quartz sand, mixtures of the sand and kaolinite, illite, and montmorillonite, and two natural soils with organic matter removed. In each test, a 200 mg L−1 nitrate–nitrogen (NO3−–N) solution was injected at the inlet of dry soil columns. Comparison of corresponding NO3−–N concentration and volumetric water content profiles from the column tests provided valuable information regarding soil mineral composition impacts on NO3− transport. With the exception of a small peak at the wetting front, NO3−–N concentrations for the quartz sand were consistently near the 200 mg L−1 injection level within the wetted portion of the columns, indicating that NO3− electrostatic interactions were negligible. Anion adsorption processes in the 25% kaolinite–75 % sand mixture produced a result in which the NO3−–N concentrations adjacent to the inlet of the columns were approximately 20% greater than that of the injected solution. Anion exclusion was the dominant electrostatic interaction affecting NO3− mobility in the 25% illite–75% sand, 25% montmorillonite–75% sand, and 15% kaolinite–7.5% illite–7.5% montmorillonite–70% sand mixtures and in the two natural soils. Evidence of anion exclusion in these artificial and natural soils includes NO3−–N concentrations near the column inlet that were 11 to 19% less than the injected solution concentration, and NO3−–N concentrations near the wetting front that were greater than the injected solution concentration by factors of 1.7 to 5.4. These results indicate that anion adsorption is an important process affecting NO3− mobility in low pH soils, with limited amounts of organic matter, and having a clay‐size fraction dominated by kaolinite, while anion exclusion is a key electrostatic interaction influencing NO3− mobility in near‐neutral to high pH soils, especially if significant amounts of montmorillonite are present.

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\begin{matrix} C = C_{0}, for λ = 0 (x = 0 and t > 0) \end{matrix}

The boundary condition given by Eq. [11] states that the NO 3 − –N inlet concentration is kept constant throughout the test.…”

Section: Resultsmentioning

confidence: 54%

Section: Resultsmentioning

confidence: 56%

mentioning

confidence: 99%

mentioning

confidence: 99%

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The Impact of Clay Mineralogy on Nitrate Mobility under Unsaturated Flow Conditions

Allred¹,

Bigham

Brown

2007

Vadose Zone Journal

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“…Generalized rate of application in agriculture is normally not beyond the 500 m 3 /ha and it has meagre probability for ground water pollution due to their absorptivity and microbial mediated oxidation of vinasse, filter mechanism of soils and low mobility rate constants of nitrate and other major anions in the soils (Allred et al, 2007;Karanam and Joshi, 2010). In Brazil, continuous application of vinasse about 300 m 3 /ha in clay loam soils for 15 years have not altered the ground water quality and leach out studies found the decreased amounts of nitrate and other pollutant at water front with depth where rate of anions mobility in soils are very low (Allred et al, 2007;Cruz et al, 1991). It is well supported by studies in India where field irrigation by 40% of treated spent wash application to sandy loam soils (Ustrochrept) found decreased spent wash concentration and chloride with soils depth (Karanam, 2001).…”

Section: Implication Of Vinasse Application In Agriculture and Groundmentioning

confidence: 99%

Significance of vinasses waste management in agriculture and environmental quality- Review

Vadivel¹,

Minhas²,

P³

et al. 2014

Afr. J. Agric. Res.

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Vinasse is a waste material from distillery industries which has lot of organic and inorganic loads. It is utilized in agriculture for cheap nutrients source, ameliorating agents and animal feed beyond the limitation of high biochemical oxygen demand (BOD; 46100 to 96000 mgL-1), chemical oxygen demand (COD; 104000 to 134400 mgL-1) and total dissolved salts (30.5 to 45.2 dSm-1) content even after the pollutant removal treatments. Vinasse treatments with combined approach of aerobic and anaerobic methods are more effective by both cost and pollutant on removal efficiency. Optimized dose of vinasse application has significance over soil properties, crop qualities and yield improvement. Globally, it has high potential to substitute potassium and nitrogen nutrients to the present level of annual consumption. It also contributes a substantial amount of phosphorous, calcium, sulphur and micronutrients to crops. In developed countries, starchy vinasse used as animal feed on a lean season to animals that improved the feed digestibility and animal quality where feed shortages are experienced. However, inadequate knowledge of vinasse properties and mode of utilization in agriculture questioned environmental quality for ground water pollution. Further research is needed to be strengthened for increased pollutant removal efficiency and diversified utilization in different cropping system (temporal scale) for effective utilization and safe disposal to the ecosystem. This article aimed to give the vinasse kinds and their characteristics features, soil-vinases interaction mechanism and its influence on plant, soil and water quality as consequence in agriculture.

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Assessment of nitrate transport parameters using the advection-diffusion cell

Aljazzar

Al‐Qinna

2016

Environ Sci Pollut Res

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This study aimed to better understand nitrate transport in the soil system in a part of the state of North Rhine-Westphalia, in Germany, and to aid in the development of groundwater protection plans. An advection-diffusion (AD) cell was used in a miscible displacement experiment setup to characterize nitrate transport in 12 different soil samples from the study area. The three nitrate sorption isotherms were tested to define the exact nitrate interaction with the soil matrix. Soils varied in their properties which in its turn explain the variations in nitrate transport rates. Soil texture and organic matter content showed to have the most important effect on nitrate recovery and retardation. The miscible displacement experiment indicated a decrease in retardation by increasing sand fraction, and an increase in retardation by increasing soil organic matter content. Soil samples with high sand fractions (up to 94 %) exhibited low nitrate sorption capacity of less than 10 %, while soils with high organic matter content showed higher sorption of about 30 %. Based on parameterization for nitrate transport equation, the pore water velocity for both sandy and loamy soils were significantly different (P < 0.001). Pore water velocity in sandy soil (about 4 × 10 m/s) was about 100 to 1000 larger than in loamy soils (8.7 × 10 m/s). On the other hand, the reduction in nitrate transport in soils associated with high organic matter was due to fine pore pathways clogged by fine organic colloids. It is expected that the existing micro-phobicity increased the nitrate recovery from 9 to 32 % resulting in maximum diffusion rates of about 3.5 × 10 m/s in sandy soils (sample number CS-04) and about 1.4 × 10 m/s in silt loam soils (sample number FS-02).

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Nitrate Mobility Under Unsaturated Flow Conditions in Four Initially Dry Soils

Cited by 17 publications

References 30 publications

The Impact of Clay Mineralogy on Nitrate Mobility under Unsaturated Flow Conditions

The Impact of Clay Mineralogy on Nitrate Mobility under Unsaturated Flow Conditions

Significance of vinasses waste management in agriculture and environmental quality- Review

Assessment of nitrate transport parameters using the advection-diffusion cell

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