soil water content Articles
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Soil moisture and metolachlor volatilization observations over three years
Received for publication June 18, 2008. A 3-yr study was conducted to focus on the impact of surface soil water content on metolachlor (2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamide) volatilization from a field with different surface soil water regimes created by subsurface water flow paths. Metolachlor vapor fluxes were measured at two locations within the field where ...
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Soil moisture and metolachlor volatilization observations over three years
Received for publication June 18, 2008. A 3-yr study was conducted to focus on the impact of surface soil water content on metolachlor (2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamide) volatilization from a field with different surface soil water regimes created by subsurface water flow paths. Metolachlor vapor fluxes were measured at two locations within the field where ...
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Validity of the centrifuge method for determining the water retention properties of tropical soils
This study compared the centrifuge and pressure plate methods with appropriate run durations. Samples collected in tropical soils located in Brazil along a 10-km local hydrosequence across the Cerrado–Amazonia transition (Set 1) and along a 350-km regional toposequence across the Cerrado region (Set 2) were selected to compare and discuss statistically the similarity of the soil water retention ...
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Soil water content and soil disaggregation by disking affects PM10 emissions
Row crop agriculture in California's San Joaquin Valley is a major contributor of particulate matter <10 µm in aerodynamic diameter (PM10). The California Air Resources Board uses fixed PM10 emission values for various tillage operations to monitor and design attainment strategies. However, fixed emission values do not reflect emissions produced by a single implement operating under different ...
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Evaluation of methane oxidation in a landfill cover material using a simple indicator approach
Estimates of methane (CH4) oxidation rates (Rg) in biocovers are crucial for development of abatement strategies. Rg values were estimated in a landfill biocover with a simple approach based on gas diffusion theory. Rg varied from 0 to 1.1 × 10−6 kg m−3 s−1. Highest oxidation efficiencies reached 80-100% when soil water content 20°C and O2 concentration > 0.1 kg m−3. Rg was correlated to ...
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Study on extinction depth and steady water storage in root zone based on lysimeter experiment and HYDRUS-1D simulation
HYDRUS-1D was combined with lysimeter experiments to study extinction depth and steady water storage in root zone (Ws) of groundwater evaporation (ETgw) under winter wheat and silt soil. The measured soil water contents and daily ETgw with various groundwater depths were used to calibrate and validate the parameters in HYDRUS-1D. In total, 13 groundwater depths ranging from 0.5 to 5.0 m were ...
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Characterizing long-term Hydrologic-response and sediment-transport for the R-5 catchment
Recently there have been several calls to establish long-term data collection networks to monitor near-surface hydrologic response and landscape evolution. The focus of this paper is a long-term dataset from the International Hydrologic Decade (1965–1974). The small upland catchment, known as R-5, located near Chickasha, Olahoma, has been the subject of considerable attention within the ...
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Simplified method for quantifying theoretical underestimation of chamber-based trace gas fluxes
Received for publication June 19, 2009. Closed chambers used to measure soil-atmosphere exchange of trace gases including nitrous oxide (N2O) and carbon dioxide (CO2) generate errors due to suppression of the gas concentration gradient at the soil-atmosphere interface. A method is described here for estimating the magnitude of flux underestimation arising from chamber deployment. The technique is ...
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Time lapse resistivity/IP survey case study
Changes in underground electric resistivity is typically resulted by the variations in groundwater conduction and soil water content. Monitoring this variation will help operator gain a better understanding of the underground water distribution over time. This may facilitates operators monitor abnormal underground or structural behaviour. Time lapse resistivity survey is therefore very useful ...
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Effect of the soil wetness state on the stomatal ozone fluxes over Hungary
A coupled Eulerian photochemical reaction-transport model and a detailed ozone dry deposition model have been utilised for the estimation of stomatal ozone fluxes over Hungary. Ozone concentrations were modelled on an unstructured triangular grid using a method of lines approach to the solution of the reaction-diffusion-advection equations describing ozone formation, transport and deposition. The ...
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A New Technique for Diffusion Testing of Unsaturated Soil
A technique is proposed for determining the coefficients of diffusion and adsorption for ions in unsaturated soils. The method integrates the single reservoir diffusion testing of saturated soil with the axis-translation technique for the control of matric suction. The procedure allows for the application of a net total stress and matric suction to the soil during the diffusion test. The use of ...
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Water dynamics and groundwater recharge in a deep vadose zone
Understanding soil water dynamics and accurately estimating groundwater recharge are essential steps in achieving efficient and sustainable management of groundwater resources in regions with deep vadose zones. The objective of this study was to understand transient data and the dynamics nature of water from deep sections at the thick vadose zone, and to estimate groundwater recharge by ...
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A comparison of two infiltration models applied to simulation of overland flow over a two-dimensional flume
At the hillslope scale, where the rill-interrill configuration plays a significant role, infiltration is one of the major hydrologic processes affecting the generation of overland flow. As such, it is important to achieve a good understanding and accurate modelling of this process. Horton's infiltration has been widely used in many hydrologic models, though it has been occasionally found ...
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A modified Green–Ampt model for water infiltration and preferential flow
Preferential flow is significant for its contribution to rapid response to hydrologic inputs at the soil surface and unsaturated zone flow, which is critical for flow generation in rainfall–runoff (RR) models. In combination with the diffuse and source-responsive flow equations, a new model for water infiltration that incorporates preferential flow is proposed in this paper. Its performance ...
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Aggregate stability and erosion response to antecedent water content of a loess soil
Soil erosion processes are affected by the erodibility of the soil and by the erosivity of the rain. The effects of rain characteristics and invariant soil properties such as texture and organic matter content on soil erosion processes are well documented. The effect of antecedent soil water content ({theta}a) on aggregate breakdown, seal formation, and subsequent soil erosion is much more ...
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Performance of infiltration swales with regard to operation in winter times in an Alpine region
In cold climate regions winter conditions significantly influence the performance of stormwater infiltration devices. Frozen soil and water storage by snow changes their operation. In this paper winter operation of a grassed infiltration swale was investigated using on-site and laboratory measurements. The field investigation of a grassed swale at a parking place in an Alpine region showed that ...
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Measuring the Soil Water Retention Curve with the Stevens pF Matric Potential Sensor and Hydra Probe II Soil Moisture Sensor
The Stevens pF Sensor is a unique matric potential probe, which is used to measure the soil water potential of a soil - the force with which water is held within the soil and how much energy is needed to overcome this force to extract water from the soil. Unlike traditional tensiometers such as gypsum blocks, the Stevens pF Sensor utilizes a patented heating element to measure soil water ...
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Nitrous oxide emission from the littoral zones of the Miyun Reservoir near Beijing, China
Large dams may be substantial contributors to greenhouse gas emissions. Nitrous oxide (N2O) is the third most important greenhouse gas but studies on N2O emission from reservoirs are limited. We measured N2O emissions and environmental factors including atmospheric pressure, wind speed, air and soil/sediment temperature, biomass, soil water content and organic matter, total nitrogen, NH4+-N ...
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Warming and drought alter soil phosphatase activity and soil P availability in a Mediterranean shrubland
Abstract We conducted a field experiment simulating the warming and drought in a Mediterranean shrubland dominated by Erica multiflora and Globularia alypum with the aim to simulate the next future climate conditions predicted by the IPCC and ecophysiological models. As P is frequently a limiting nutrient in Mediterranean ecosystems, we investigated the drought and warming effects on soil ...
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Effect of water seal on reducing 1,3-Dichloropropene emissions from different soil textures
Received for publication February 19, 2008. Soil physical conditions can affect diffusion, environmental fate, and efficacy of fumigants in soil disinfestation treatments. Water seals (applying water using sprinklers to soil following fumigation) can effectively reduce fumigant emissions from sandy loam soils. Soil column studies compared the effectiveness of water seals in reducing ...
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