Mass balance analysis and water quality model development for paddy field were performed using field experimental data during 2001-2002. About half (47-62%) of the total outflow was lost by surface drainage, with the remainder (490-530 mm) occurring by evapotranspiration. Most of nutrient inflow and outflow were mediated by fertilization and plant uptake, respectively. Nutrient outflow by surfa...

Subsurface drainage involves both intensity and capacity attributes. Intensity of subsurface drainage refers to how rapidly a root zone drains. Capacity, on the other hand, refers to the extent of excess (gravitational) water removal from the root zone. Consequently, discussions of putting green drainage often become confused since the expression improved drainage can imply improved drainage ca...

Current practices for handling drainage water in the western San Joaquin Valley (WSJV) are not sustainable. The soil quality of 300,000 ha of land in the WSJV is adversely affected by the presence of shallow or perched water (0 to 1.5 m). Without a means of disposing of drainage water, increasing amounts of farmland in the WSJV will become salt impaired, and will be removed from production. Usi...

An experimental method was developed to measure both steam-water and air-water capillary pressures using an X-ray CT technique. We conducted spontaneous water imbibition and gravity drainage in ceramic core samples for steam-water and air-water systems respectively. The results were compared, and it was found that the steam-water capillary pressures were significantly less than the airwater cap...

Subsurface agricultural drainage has allowed for enhanced crop production in many areas of the world including the upper Midwest, United States. However, the presence of nitrate-nitrogen (nitrate-N) in subsurface tile drainage water is a topic of intense scrutiny due to several water quality issues. Many studies have been conducted looking at ways to reduce nitrate-N in tile drainage (Baker et ...

PURPOSE To assess the efficacy of an adjustable inspiratory occlusion valve in experimental bronchopleural fistula during mechanical ventilation. METHODS We studied six mechanically ventilated pigs in a surgically created, reproducible model of bronchopleural fistula managed with mechanical ventilation and water-sealed thoracic drainage. An adjustable inspiratory occlusion valve was placed be...

The relation between the sodium adsorption ratio (SAR) and pHc derived here predicts SAR of the drainage water (SARdw) better than existing empirical equations. Inaccuracies in SAR estimates from the new relationship can be anticipated by the extent to which the derived conditions are valid. Empirical equations provide no understanding of why they are sometimes inaccurate. Due to the relative i...