Many different models and mechanisms of water imbibition into soil have been described in the literature. Theoretical equations based on those models exist to predict how water will flow in porous media. These models can be useful, but have their weaknesses. Research on imbibition and infiltration into soils has mostly...
Evaporation from bare soil was investigated using a numeric model In one set of simulations, texture and evaporative demand were analyzed as they impacted short and long term evaporation. The effect of these factors on water redistribution was also analyzed. A second set of simulations was run to determine the...
Evaporation synergy is the phenomenon in which two porous medium textures that share a common vertical boundary experience a higher cumulative evaporation than either homogeneous texture can produce. Studies that have been conducted to date address this phenomenon in relatively fine and coarse sands but not in finer textured soils...
Irrigated agricultural production in sandy soils presents several unique challenges to growers, including naturally high permeability, low native water retention, as well as high rates of water drainage losses and leaching of chemicals to the shallow aquifers. This study is an initial investigation into water motion in the sandy agricultural...
Soil solarization trials were conducted during the growing seasons of 2016-2018 with the purpose of determining if solarization was an effective pre-planting soil disinfestation technique for tree nurseries in the Pacific Northwest. A large data set was collected on soil properties and biological indicators from 5 interdisciplinary experiments. This thesis...
This study focuses on one widespread characteristic of poor soil quality: hydrophobic soil. Previous research has produced conclusive evidence to show that soil hydrophobicity is affected by soil organic matter (SOM) and soil water content (WC). Hydrophobicity that responds to changes in WC is a unique form of surface hydrophobicity...
It is known that soil biota affects water dynamics through various complex mechanisms. The impact on retention by soil biota are due to a combination of changes to pore geometry, pore clogging by biofilms, biofilms that serve to connect thin water films across many pores as the soil dries, and...
The extent of agricultural drainage has created concern for its potential undesirable effects on surface water quality. Land applications of liquid manure on tile drain fields have the potential to transport solutes and bacteria to the drains following precipitation or irrigation events and many times are directly sent to a...
Many species of rodents and insectivores live in subterranean burrows in soils throughout the world. The soil surface perforations of burrow entrances are often connected to complex, subsurface tunnel networks. Burrow entrances and associated subsurface tunnel networks represent a link between surface and subsurface ecological function. Anecdotal observations of surface-water...
Evapotranspiration (ET) is the process by which water is transferred from land to the atmosphere. ET is the second most important component of a hydrologic budget and remains difficult to estimate. The primary objective of this project was to determine the limitations of estimating ET from water table elevation fluctuations...