Soil Science Commons^™

Exploration Of Lignin-Based Superabsorbent Polymers (Hydrogels) For Soil Water Management And As A Carrier For Delivering Rhizobium Spp., Toby Adjuik

Theses and Dissertations--Biosystems and Agricultural Engineering

Superabsorbent polymers (hydrogels) as soil amendments may improve soil hydraulic properties and act as carrier materials beneficial to soil microorganisms. Researchers have mostly explored synthetic hydrogels which may not be environmentally sustainable. This dissertation focused on the development and application of lignin-based hydrogels as sustainable soil amendments. This dissertation also explores the development of pedotransfer transfer functions (PTFs) for predicting saturated hydraulic conductivity using statistical and machine learning methods with a publicly available large data set. A lignin-based hydrogel was synthesized, and its impact on soil water retention was determined in silt loam and loamy fine sand soils. Hydrogel treatment …

Assessing Machine Learning Utility In Predicting Hydrologic And Nitrate Dynamics In Karst Agroecosystems, Timothy Mcgill

Theses and Dissertations--Biosystems and Agricultural Engineering

Seasonal hypoxia in the Gulf of Mexico and harmful algal blooms experienced in many inland freshwater bodies is partially driven due to excessive nitrogen loading seen from agricultural watersheds. Within the Mississippi/Atchafalaya River Basin, many areas are underlain with karst features, and efforts to reduce nitrogen contributions from these areas have had varying success, due to lacking a complete understanding of nutrient dynamics in karst agricultural systems. To improve the understanding of nitrogen cycling in these systems, 35 months of high resolution in situ water quality and atmospheric data were collected and fed into a two-hidden layer extreme learning machine …

Spatial Estimation Of Hydraulic Properties In Structured Soils At The Field Scale, Xi Zhang

Theses and Dissertations--Plant and Soil Sciences

Improving agricultural water management is important for conserving water during dry seasons, using limited water resources in the most efficient way, and minimizing environmental risks (e.g., leaching, surface runoff). The understanding of water movement in different zones of agricultural production fields is crucial to developing an effective irrigation strategy. This work centered on optimizing field water management by characterizing the spatial patterns of soil hydraulic properties. Soil hydraulic conductivity was measured across different zones in a farmer’s field, and its spatial variability was investigated by using geostatistical techniques. Since direct measurement of hydraulic conductivity is time-consuming and arduous, pedo-transfer functions …

Adjustment And Optimization Of The Cropping Systems Under Water Constraint, Pingli An, Wei Ren, Xiliin Liu, Mengmei Song, Xuemin Li

Plant and Soil Sciences Faculty Publications

The water constraint on agricultural production receives growing concern with the increasingly sharp contradiction between demand and supply of water resources. How to mitigate and adapt to potential water constraint is one of the key issues for ensuring food security and achieving sustainable agriculture in the context of climate change. It has been suggested that adjustment and optimization of cropping systems could be an effective measure to improve water management and ensure food security. However, a knowledge gap still exists in how to quantify potential water constraint and how to select appropriate cropping systems. Here, we proposed a concept of …

Effect Of Low And High- Kinetic Energy Wetting On Quality Of Sediment Produced By Interrill Erosion, Eduardo Abel Rienzi

University of Kentucky Doctoral Dissertations

Raindrop kinetic energy and sheet flow can disintegrate aggregates during interrill erosion, a process responsible for non point source pollution. Also, the dissolution process during aggregate wetting can affect interrill erosion. These factors can be responsible for changes in particle size distribution in the sediment, especially when different tillage systems are compared. The effect of soil tillage and management on soil properties is not uniform, which determine a wide range of runoff and sediment delivery rate. Variety in these rates can be associated with pore functions and their interactions with aggregate stability. One of the objectives of this study was …

Modeling Transport Of Colloid-Bound Herbicides And Heavy Metals To Groundwater, Anastasios D. Karathanasis, R. E. Phillips, A. K. Seta

KWRRI Research Reports

Recent studies have suggested that contaminant transport to groundwater may be enhanced by association with colloidal particles. This study evaluated the role of water dispersible colloids with diverse mineralogical composition in co-transporting selected herbicides and heavy metals through intact soil columns. Colloid recovery in the eluents ranged from 45-90% for the herbicides and 10-60% for the heavy metals. The presence of colloids enhanced the transport of atrazine by 2-18%, and metolachlor by 8-30%. The corresponding increase for Cu and Zn was 2-150 and 5-30 times, respectively. For Pb, there was essentially no elution in the absence of colloids, suggesting nearly …

Groundwater Study: Toyota Motor Manufacturing, Usa Georgetown, Kentucky, Gary Felton, Lyle V. A. Sendlein, Teri Dowdy, Daryl Hines

KWRRI Research Reports

An eighteen month study of the Toyota Motor Manufacturing (TMM) plant site and the surrounding area was undertaken. The basic charge for this project was to characterize the groundwater that is potentially impacted by the TMM plant site. This included occurrence, flow direction, and, if possible, velocity. Because the area is karstified (has sinkholes, springs, caves, etc.) surface water and groundwater are intimately connected and, hence, surface water was frequently an important component of this work.

Data from TMM construction plans and monitoring work done subsequent to construction were elicited from the various repositories within the TMM infrastructure. Aerial color …

Use Of Riparian Vegetated Filter Strips To Reduce Nitrate And Fecal Contamination In Surface Water, Mark S. Coyne, Robert L. Blevins, Rebecca A. Gilfillen

KWRRI Research Reports

This research assessed fecal bacteria trapping in surface runoff by grass filters and their potential to enhance NO₃^- removal via denitrification. Grass filter strips 9.0 m long trapped over 99% of the soil in surface runoff in 1992. Fecal coliform removal was less than 75%. In 1993, 9.0 and 4.5 m grass filter strips trapped 99 and 95% of the sediment, respectively. Fecal coliform trapping efficiency was 90% in 9.0 m grass filters and 75% in 4.5 m filters. Fecal streptococci trapping efficiency was 77% in 9.0 m grass filters and only 56% in 4.5 m filters. Fecal …

Kinetics And Mechanisms Of Atrazine Adsorption And Desorption In Soils Under No-Till And Conventional Management, V. P. Evangelou, W. W. Witt, E. Portig, Mike Barrett

KWRRI Research Reports

Both soils (Maury silt loam and Sadler) exhibited three apparent mechanisms of atrazine adsorption. The first two mechanisms were very rapid (10 minutes) and were assigned to soil-clay surface adsorption reactions via hydrogen bonding. The quantity of atrazine involved in these two reactions for the 0.5 mg/1 solution atrazine varied, depending on the soil, from 67 μg/100 g clay to 219 μg/100 g clay. The reason there were two possible atrazine sinks in this range of atrazine adsorption was believed to be the presence of two types of reactive surfaces, the clay inorganic phase and the organic carbon phase. The …

Modeling Mass Transport In Aquifers: The Distributed Source Problem, Sergio E. Serrano

KWRRI Research Reports

This report presents a new methodology to model the time and space evolution of groundwater variables in a system of aquifers when certain components of the model, such as the geohydrologic information, the boundary conditions, the magnitude and variability of the sources or physical parameters are uncertain and defined in stochastic terms. This facilitates a more realistic statistical representation of groundwater flow and groundwater pollution forecasting for either the saturated or the unsaturated zone. The method is based on applications of modern mathematics to the solution of the resulting stochastic transport equations. This procedure exhibits considerable advantages over the existing …

Predicting Infiltration And Surface Runoff From Reconstructed Spoils And Soils, Larry G. Wells, Andrew D. Ward, Ronald E. Phillips

KWRRI Research Reports

A laboratory system was fabricated to measure infiltration and runoff from spoil and soil profiles constructed in rectangular bins. Construction, calibration and operation of a rainfall simulator is discussed and instrumentation used to measure transient infiltration and transmittance of water through experimental profiles is described.

Spoil and soil materials from surface mines in Eastern and Western Kentucky were transported to the laboratory and used in constructing experimental profiles in rectangular bins (0.91 x 1.83 x 1.07 m). An extensive series of infiltration experiments were conducted utilizing a rainfall simulator and soil moisture monitoring instrumentation. A dual probe gamma density gauge …

Modeling Soil Water Contents And Their Effects On Stream Flow In Kentucky, Grant W. Thomas, Ronald E. Phillips, David E. Radcliffe, Scott Shepard

KWRRI Research Reports

Soil water contents of eight important soil series in Kentucky were measured periodically during the summer growing season for four years, 1977 through 1980. The soils divided into three groups according to their behavior. The first group (Maury and Crider) is well-drained and never showed excess water above field capacity at any time during the four seasons. The second group (Zanesville, Lowell, Calloway, Grenada and Shelbyville) showed perched water tables at times, especially during the early part of the growing season. The third group was represented by the Huntington soil which has a permanent water table.

The in-situ field capacity …

Influence Of Nitrogen Fertilization On The Quality And Quantity Of Streamflow From A Forested Watershed, George B. Coltharp, Michael T. Shearer, Everett P. Springer, Robert F. Wittwer

KWRRI Research Reports

This project was designed to determine the effects of nitrogen fertilization on the quality and quantity of streamflow eminating from an eastern hardwood forest watershed. A 40.67 ha watershed, located in mountainous eastern Kentucky, was aerially fertilized in late April 1975. The forest stand was principally oak, hickory, and yellow poplar, 50 - 55 years of age and in a relatively undisturbed condition. A helicopter applied anunonium nitrate at a rate of 504 kg/ha. Because a large part of applied nitrogen fertilizer ends up in the highly mobile nitrate nitrogen.form, this is the principal ion monitored in this study. No …

Effects Of Soil Injection Of Liquid Dairy Manure On The Quality Of Surface Runoff, I. J. Ross, S. Sizemore, J. P. Bowden, C. T. Haan

KWRRI Research Reports

Liquid dairy manure has been injected on the soil contour to depths of 6 and 12 inches and applied to the surface of a Bluegrass sod and a bare tilled soil. Application rates of 9,250 gallons per acre were used. Runoff from 9-foot-square plots which were sprinkled at rates of 2.5 inches per hour on sod and 1.5 inches per hour on bare soil was collected and analyzed for various pollution parameters including COD, N, TS, TSS, pH, DO, and Fecal Coliform. The effects of pollutant yield in the runoff have been determined for various treatments.

Injection of the manure …

Characterization Of Water Movement Into And Through Soils During And Immediately After Rainstorms, C. T. Haan

KWRRI Research Reports

The movement of water into and through soils in the unsaturated state is basic to many water resources problems including rainfall-runoff models, ground water recharge, irrigation, drainage, evapotranspiration and the movement of pollutants in soils. This study was conducted in an effort to determine if the flow equation based on Darcy's Law and the continuity equation could be used to describe watershed infiltration and thus be incorporated into hydrologic models.

The results of the study indicate that even on apparently uniform soils there is a great deal of variability in soil water properties. Handling this variability plus the difficulty of …

The Relation Between Soil Characteristics, Water Movement And Nitrate Contamination Of Ground Water, Grant W. Thomas, Matthew Mcmahon

KWRRI Research Reports

Soils from several areas in Kentucky were placed in columns and leached with Ca(NO₃)₂. Subsoils high in iron oxide were found to retard the leaching of nitrate very significantly. In other soils, the nitrate moved through as fast as or slightly faster than the water.

Field application of nitrogen to corn was most efficient when done in the spring or summer near the time that the corn takes it up. The one exception to this was a red soil, where fall application of nitrogen resulted in little loss due to the retarding effect mentioned in the …

Location Of Solution Channels And Sinkholes At Dam Sites And Backwater Areas By Seismic Methods: Part Ii, Vincent P. Drnevich, D. Raghu

KWRRI Research Reports

Four seismic field methods and a laboratory method are used to determine shear wave propagation velocities and shear moduli for two sites. The four seismic methods are: standard seismic refraction survey, down hole shooting refraction survey, transient Rayleigh wave survey, and crosshole shooting survey. A torsional resonant column apparatus was used for the laboratory tests. The cross hole shooting method gave the best results because direct measurements were made. Criteria for using this method are given. Methods which measure compression wave velocity give inconsistent results because the conversion to shear wave velocity is very sensitive to Poisson's ratio. Laboratory tests …

Location Of Solution Channels And Sinkholes At Dam Sites And Backwater Areas By Seismic Methods: Part I, Vincent P. Drnevich, S. R. Smith, E. P. Cleveland

KWRRI Research Reports

The basic concepts associated with the sledge hammer seismic refraction survey are reviewed and a modified version called down hole shooting is discussed. The latter method has distinct advantages for rock surface profiling. These include: calibration at the end points of the survey, measurement of vertical wave propagation velocities directly, and having a refracted wave ray path for almost the entire survey length.

The down hole shooting seismic refraction survey has been simulated with the digital computer. The method can handle any shaped rock surface profile and generates corresponding travel time curves for the forward and reverse profile surveys. This …

Capillary-Diffusion And Self-Diffusion Of Liquid Water In Unsaturated Soils, Ronald E. Phillips, V. L. Quisenberry Jr.

KWRRI Research Reports

Capillary-diffusion coefficients were measured by use of inflow and outflow methods. With both methods the capillary-diffusion coefficients decreased very rapidly with decreasing water content. The lighter textured soils were found to have the higher diffusion coefficients over the entire moisture content range studied, 0 to 1 bar tension.

Self-diffusion coefficients were measured over a moisture content range from air dryness to saturation using ³H as a tracer of water. Each of the soils gave the same diffusion characteristics when the self-diffusion coefficients were expressed as a function of either water content or average number of water layers on the …

Part I - Controlling The Soil Moisture Environment Of Transpiring Plants, Part Ii - Prediction Of Leaf Temperature Under Natural Atmospheric Conditions, Charles T. Haan, Billy J. Barfield, Robert Edling

KWRRI Research Reports

Part I

A technique for controlling the soil moisture potential in the root zone of transpiring plants was developed. The method uses the principles of unsaturated flow through a porous media to develop the desired moisture potential. In the case of non-steady state transpiration, the maximum possible fluctuation in the soil moisture potential can be determined by the techniques presented.

Part II

Two implicit leaf temperature prediction equations were derived from the energy balance approach. The equations define sensible and latent heat transfer from a plant population as a two step process:

1. Transfer between the plant leaf and the canopy …