Bacterial leaching from dairy shed effluent applied to a fine sandy loam under irrigated pasture

Soil Research ◽  
2008 ◽  
Vol 46 (7) ◽  
pp. 552 ◽  
Author(s):  
Shuang Jiang ◽  
Graeme D. Buchan ◽  
Mike J. Noonan ◽  
Neil Smith ◽  
Liping Pang ◽  
...  
Keyword(s):  
Water Content ◽  
Water Flow ◽  
Sandy Loam ◽  
Volumetric Water Content ◽  
Faecal Coliform ◽  
Bacterial Transport ◽  
Flood Irrigation ◽  
Bacterial Leaching ◽  
Fine Sandy Loam ◽  
Spray Irrigation

This experiment investigated bacterial transport from land-applied dairy shed effluent (DSE), via field lysimeter studies, using 2 contrasting irrigation methods. Transient water flow and bacterial transport were studied, and the factors controlling faecal coliform (FC) transport are discussed. Two trials (Trial 1, summer; Trial 2, autumn) were carried out, using 6 undisturbed soil monolith lysimeters, 500 mm diameter by 700 mm deep, with a free-draining, Templeton fine sandy loam. DSE with inert chemical tracers was applied at the start of both trials using the same method, followed with repeated 14-day cycles of either flood or spray irrigation of water. A bacterial tracer, antibiotic-resistant faecal coliform, was added to the DSE in Trial 2 only, to distinguish applied FC from external or resident FC. Leachates were collected after each water application (or heavy rainfall when applicable) for enumeration of FC and measurement of tracers. All lysimeters were instrumented for monitoring volumetric water content, matric potential, and soil temperature at 4 depths (100, 250, 450, and 600 mm). The results showed that bacteria could readily penetrate through 700-mm-deep soil columns, when facilitated by water flow. The highest post-water irrigation concentration was 3.4 × 103 cfu/100 mL under flood irrigation, which resulted in more bacterial and Br– leaching than spray irrigation. Trial 2 (autumn) results also showed significant differences between irrigation treatments in lysimeters sharing similar drainage class (moderate or moderately rapid), flood irrigation again gave more bacterial and tracer (Cl–) leaching. In the summer trial, FC in leachate as high as 1.4 × 106 cfu/100 mL, similar to the concentration of DSE, was detected in one lysimeter that had a higher clay content in the topsoil immediately after DSE application, and before any water irrigation. This indicates that applied DSE leached through preferential flow paths without any dilution. Bacterial concentration in the leachate was positively correlated with both volumetric water content and water potential, and sometimes drainage rate. Greater bacterial leaching was found in the lysimeter with rapid whole-column effective hydraulic conductivity, Keff, for both flood and spray treatments. Occasionally, the effect of Keff on water movement and bacterial transport overrode the effect of irrigation. The ‘seasonal condition’ of the soil (including variation in initial water content) also influenced bacterial leaching, with less risk of leaching in autumn than in summer. These findings contribute to our increased understanding of bacterial transport processes on the field scale.

HYDRUS (2d/3d) simulation of water flow through sandy loam soil under potato cultivation in Southern Manitoba

2017 ◽  
pp. 1.9-1.19 ◽  
Author(s):  
Afua Mante ◽  
Ramanathan Sri Ranjan
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Flow ◽  
Sandy Loam ◽  
Crop Evapotranspiration ◽  
Reference Crop Evapotranspiration ◽  
Loam Soil ◽  
Flow Through ◽  
Reference Crop

The HYDRUS (2D/3D) modeling tool was used to simulate water flow through subsurface-drained sandy loam soil under potato (Solanum tuberosum) cultivation in Southern Manitoba. The model was used to simulate water flow through a 2-D model domain of dimensions, 15 m width × 2.5 m depth. The model was calibrated and validated with field data measured during the growing season of year 2011 at the Hespler Farms, Winkler, Manitoba. Field measurements, including soil water content and watertable depth, for two test plots under subsurface free drainage were used for the calibration and validation. Weather data were also obtained to estimate reference crop evapotranspiration, which was used as input data in the model. Based on the reference crop evapotranspiration, and crop coefficient of the potato crop, the actual crop evapotranspiration was estimated and compared to the simulated actual crop evapotranspiration results. The results showed that the model was able to account for 50% to 78% of the variation in the estimated actual crop evapotranspiration. With respect to water flow through the soil, the observed soil water content and the simulated soil water content were compared using graphical and quantitative analysis. Based on the coefficient of determination (R2), the model accounted for 68% to 89% variation in the observed data. The intercept of the regression line varied from 0.01 to 0.08, and the slope, 0.75 to 0.99. The Nash–Sutcliffe modeling efficiency coefficient (NSE) varied from 0.62-0.89, the Percent bias (PBIAS) values varied from -1.99% to 1.16%. The root mean square error-observations standard deviation ratio (RSR) values varied from 0.33 to 0.61. The values for the evaluation parameters show that the model was able to simulate the water flow through the soil profile reasonably well.

scholarly journals Effect of Soil Types on The Development of Matric Suction and Volumetric Water Content for Dike Embankment During Overtopping Tests

2018 ◽  
Vol 4 (3) ◽  
pp. 668 ◽  
Author(s):  
Marwan Adil Hassan ◽  
Mohd Ashraf Mohamad Ismail
Keyword(s):  
Water Content ◽  
Water Flow ◽  
Fine Particles ◽  
Side Wall ◽  
Matric Suction ◽  
Volumetric Water Content ◽  
Silty Sand ◽  
Soil Types ◽  
The Stability ◽  
The University

The resistance of dike materials has a great effect on the development of hydraulic engineering around the world. It helps to understand the mechanism of dike failure occurred due to the influence of hydraulics and Geotechnical parameters. The overtopping moment is one of the main failures that reduces the stability of the dike embankment through initiating the breach channel inside dike crest as a result of water flow above the downstream slope of the dike. Two spatial overtopping tests were conducted at in Hydraulic Geotechnical laboratories at the University Sains of Malaysia to observe the evolution of matric suction and volumetric water content for two soil types of sand and very silty sand soils. A pilot channel was cut in dike crest along the side wall of the small flume channel to represent the transition water flow from upstream into downstream slopes during overtopping test. The results indicated that the matric suction decreases due to the increase of volumetric water content during the saturation of dike body. The proportion increasing and decreasing of volumetric water content and matric suction is lower in very silty sand than those in sand soil due to the presence of fine particles in previous soil.

scholarly journals An Investigation of the Accuracy of EC5 and 5TE Capacitance Sensors for Soil Moisture Monitoring in Urban Soils-Laboratory and Field Calibration

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6510
Author(s):  
Tala Kanso ◽  
Marie-Christine Gromaire ◽  
David Ramier ◽  
Philippe Dubois ◽  
Ghassan Chebbo
Keyword(s):  
Soil Moisture ◽  
Water Content ◽  
Urban Soils ◽  
Sandy Loam ◽  
Calibration Method ◽  
Volumetric Water Content ◽  
Calibration Data ◽  
Undisturbed Soil ◽  
Field Calibration ◽  
Calibration Methods

Recently, emphasis has been placed on finding a reliable estimation of soil water content. In this study, two capacitance sensors EC5 and 5TE (METER Group) were utilized. These sensors provide many benefits relative to other sensors in that they are cost-effective and very economical regarding energy use, operate at a high measurement frequency of 70 MHz, and are dedicated to measuring at a small volume because of their small size. This makes them suitable for the context of use in this research, which consists of multiple sustainable drainage systems SuDS. Several studies have evaluated these two types of sensor but not for urban soils with specific characteristics. In addition, results from the literature are divergent and the published calibration data are limited. Therefore, an in-depth investigation of their accuracy is assessed in this paper. At first, the literature’s existing procedures and methods were examined. The sensor-to-sensor variability, as well as repeatability, were tested in soil and solutions. Additionally, a field calibration method was conducted to estimate the effects of soil texture on sensors readings. Two laboratory calibration methods having different principles were also applied, compared to each other and to the field calibration as well. Results revealed weak sensor-to-sensor variability (coefficient of variation up to 15% in soil) and also good repeatability (0.1%), for both sensors. A soil-specific calibration equation has improved the estimation of the volumetric water content. In case of soil having high field bulk density, the undisturbed soil calibration method described and proposed in this paper gives promising results. The latter method yields a volumetric water content (VWC) prediction accuracy of 0.025 m3∙m−3 on a sandy loam soil. This paper presents a large knowledge of capacitance sensors measurement technique as well as their calibration procedures and methods. Limitations of existing procedures have been identified and key elements for selecting the appropriate one are suggested. Derived calibration equations have also been provided for three urban soils with different particle size distribution, ranging from sandy loam to silt loam. Accurate monitoring of soil moisture content in urban soils is thus achievable.

New Method for Estimation of Contaminant Travel Rate in Unsaturated Zone under Irrigated Soils

1993 ◽  
Vol 27 (7-8) ◽  
pp. 173-178 ◽  
Author(s):  
M. Zilberbrand
Keyword(s):  
Water Content ◽  
Unsaturated Zone ◽  
Sandy Loam ◽  
Chestnut Soil ◽  
Deep Penetration ◽  
Groundwater Recharge Rate ◽  
Capillary Tension ◽  
Travel Rate ◽  
Tracer Experiments ◽  
Irrigated Soils

In a thick unsaturated zone, when quick deep penetration of rain and irrigation water is absent, at the depths below 3-5 m there exists a zone of downwards quasi-steady water flow. Darcy's water velocity in this zone remains constant with depth and equal to the groundwater recharge rate; unit hydraulic head gradient occurs above the capillary fringe. Therefore, contaminant travel rate is equal to the ratio of hydraulic conductivity (K) and effective volumetric water content (θef). Field tracer experiments and laboratory K and θef determinations were carried out for several representative irrigated lots in the South Ukraine. The dependence of θef on capillary tension was studied for the first time. For loess loam with a capillary tension decreasing from 46 kPa to 0, θef nonlinearly increases from 12% to 27-28%. The effective water content portion (β1) of the total water content increases nonlinearly from 0.38 to 0.65-0.7. The β1 values were estimated for different unsaturated sedimentary rocks. For a capillary tension of about 5 kPa β1 values were: 0.88-0.99 for sands, about 0.65 for loess loam and chestnut soil, about 0.6 for sandy loam, about 0.32 for limestone and about 0.07 for clay. Calculated chloride travel rates in loess loams under irrigated soils fit the values of 0.001-0.003 m/day, determined by the results of field tracer experiments.

Data Assimilation with Soil Water Content Sensors and Pedotransfer Functions in Soil Water Flow Modeling

2012 ◽  
Vol 76 (3) ◽  
pp. 829-844 ◽  
Author(s):  
Feng Pan ◽  
Yakov Pachepsky ◽  
Diederik Jacques ◽  
Andrey Guber ◽  
Robert L. Hill
Keyword(s):  
Data Assimilation ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Flow ◽  
Pedotransfer Functions ◽  
Flow Modeling ◽  
Soil Water Flow

THE EFFECT OF ANTECEDENT FREEZE-THAW FREQUENCY ON RUNOFF AND SOIL LOSS FROM FROZEN SOIL WITH AND WITHOUT SUBSOIL COMPACTION AND GROUND COVER

1989 ◽  
Vol 69 (4) ◽  
pp. 799-811 ◽  
Author(s):  
LINNELL M. EDWARDS ◽  
J. R. BURNEY
Keyword(s):  
Prince Edward Island ◽  
Sandy Loam ◽  
Bare Soil ◽  
Winter Rye ◽  
Rainfall Simulator ◽  
Fine Sandy Loam ◽  
Freeze Thaw ◽  
Sediment Loss ◽  
Freezing Period ◽  
Subsoil Compaction

Three soils from Prince Edward Island (a loam, a fine sandy loam, and a sandy loam) were tested under a laboratory rainfall simulator to examine the effects of frequency of freezing and thawing, winter rye cover, incorporated cereal residue, and subsoil compaction on runoff volume and sediment loss. Wooden soil boxes were subjected to simulated rain (i) at the end of a 10-d freezing period, and (ii) at the end of the 5th 24-h freezing period of a 10-d alternating freeze-thaw cycle (freeze/thaw). Where the soil was continuously frozen for 10 d, there was 178% greater sediment loss and 160% greater runoff than with daily freeze/thaw over the same period, but there was no difference in sediment concentration. Incorporated cereal residue decreased sediment loss to 50% and runoff to 77% of that from bare soil. Winter rye cover decreased sediment loss to 73% of that from bare soil. Simulated soil compaction caused a 45% increase in sediment loss. The loam soil showed 16.5% greater loss of fine sediment fractions <0.075 mm than the fine sandy loam which showed 23.4% greater loss than the sandy loam. Key words: Freeze-thaw, erosion, compaction, winter rye, cereal residue, rainfall simulator, Prince Edward Island soils

Using time domain reflectometry in triaxial testing

2000 ◽  
Vol 37 (6) ◽  
pp. 1325-1331
Author(s):  
J LH Grozic ◽  
M E Lefebvre ◽  
P K Robertson ◽  
N R Morgenstern
Keyword(s):  
Cyclic Loading ◽  
Water Content ◽  
Time Domain ◽  
Void Ratio ◽  
Time Domain Reflectometry ◽  
Volumetric Water Content ◽  
Degree Of Saturation ◽  
Triaxial Testing ◽  
Empirical Correlations ◽  
Static And Cyclic Loading

Time domain reflectometry (TDR) can be used to determine the volumetric water content of soils. This note describes the utilization of a TDR miniprobe in triaxial testing. The TDR performance was examined with a series of tests that not only proved its reliability but also resulted in two empirical correlations. Using these correlations, the degree of saturation and volumetric water content during triaxial testing could be determined. The TDR was then put to use in a laboratory program designed to investigate the response of loose gassy sand under static and cyclic loading. Because of the TDR measurements it was possible to determine the degree of saturation and void ratio of the gassy specimens. The TDR miniprobe proved to be accurate, simple to use, and inexpensive to build.Key words: time domain reflectometry, TDR, triaxial testing, gassy, unsaturated.

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