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Soil moisture

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Full-Text Articles in Physical Sciences and Mathematics

Estimation Of The Effects Of Climate Variability On Crop Yield In The Midwest Usa, Ruoyu Wang Nov 2015

Estimation Of The Effects Of Climate Variability On Crop Yield In The Midwest Usa, Ruoyu Wang

Ruoyu Wang

Crop yield is strongly affected by climate variability. When applying ecohydrologic models to study climate impacts on crop yield, especially interannual yield responses to climate stresses, the model simulation of plant available soil moisture must be constrained in order to reproduce plant production variation via moisture related bio-climate variables. In this study, the Soil and Water Assessment Tool (SWAT) is used to investigate the relationship between climate variability and crop yield at four sites (Boone, Woodbury, Madison, and Mason) in the Midwestern USA. The model was first calibrated for soil moisture at the plot scale. The calibrated model was then …

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Soil Water Potential Control Of The Relationship Between Moisture And Greenhouse Gas Fluxes In Corn-Soybean Field, Dinesh Panday, Nsalambi V. Nkongolo Aug 2015

Soil Water Potential Control Of The Relationship Between Moisture And Greenhouse Gas Fluxes In Corn-Soybean Field, Dinesh Panday, Nsalambi V. Nkongolo

Dinesh Panday

Soil water potential (Ψ) controls the dynamics of water in soils and can therefore affect greenhouse gas fluxes. We examined the relationship between soil moisture content (θ) at five different levels of water potential (Ψ = 0, −0.05, −0.1, −0.33 and −15 bar) and greenhouse gas (carbon dioxide, CO2; nitrous oxide, N2O and methane, CH4) fluxes. The study was conducted in 2011 in a silt loam soil at Freeman farm of Lincoln University. Soil samples were collected at two depths: 0–10 and 10–20 cm and their bulk densities were measured. Samples were later saturated then brought into a pressure plate …

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Reproducibility Of Soil Moisture Ensembles When Representing Soil Parameter Uncertainty Using A Latin Hypercube–Based Approach With Correlation Control, Alejandro N. Flores, Dara Entekhabi, Rafael L. Bras Apr 2010

Reproducibility Of Soil Moisture Ensembles When Representing Soil Parameter Uncertainty Using A Latin Hypercube–Based Approach With Correlation Control, Alejandro N. Flores, Dara Entekhabi, Rafael L. Bras

Alejandro N. Flores

Representation of model input uncertainty is critical in ensemble-based data assimilation. Monte Carlo sampling of model inputs produces uncertainty in the hydrologic state through the model dynamics. Small Monte Carlo ensemble sizes are desirable because of model complexity and dimensionality but potentially lead to sampling errors and correspondingly poor representation of probabilistic structure of the hydrologic state. We compare two techniques to sample soil hydraulic and thermal properties (SHTPs): (1) Latin Hypercube (LH) based sampling with correlation control and (2) random sampling from SHTP marginal distributions. A hydrology model is used to project SHTP uncertainty onto the soil moisture state …

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