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University of Kentucky

1998

Articles 1 - 10 of 10

Full-Text Articles in Soil Science

Comparison Of Water And Temperature Distribution Profiles Under Sand Tube Irrigation, Masoud Meshkat, Richard C. Warner, Stephen R. Workman Nov 1998

Comparison Of Water And Temperature Distribution Profiles Under Sand Tube Irrigation, Masoud Meshkat, Richard C. Warner, Stephen R. Workman

Biosystems and Agricultural Engineering Faculty Publications

Drip irrigation is one of the most efficient systems in delivering water to the plant root zone. Research has shown that the saturated, or nearly saturated, surface beneath the emitter may increase evaporation thereby reducing the irrigation efficiency. To increase the efficiency of surface applied drip irrigation on permanent tree crops a sand tube irrigation (STI) method was developed and tested. The sand tube method consists of removing a soil core beneath the emitter and filling the void with coarse sand. A weighing lysimeter was designed and instrumented to directly measure temporal evaporation during irrigation and for a period of …

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Quality Of Runoff From Plots Treated With Municipal Sludge And Horse Bedding, Elizabeth L. Busheé, Dwayne R. Edwards, Philip A. Moore Jr. Jul 1998

Quality Of Runoff From Plots Treated With Municipal Sludge And Horse Bedding, Elizabeth L. Busheé, Dwayne R. Edwards, Philip A. Moore Jr.

Biosystems and Agricultural Engineering Faculty Publications

Land application of horse stall bedding and municipal sludge can increase runoff concentrations of nutrients, organic matter, and bacteria as well as steroidal hormones such as estrogen. Concentrations of materials in runoff from sites treated with animal manure can be reduced by aluminum sulfate, or alum [Al2(SO4)3•14H2O] treatment. The objectives of this study were to assess plots treated with horse stall bedding or municipal sludge for: (a) runoff quality [concentrations of nitrate nitrogen (NO3-N), ammonia nitrogen (NH3-N), orthophosphate-phosphorus (PO4-P), fecal coliform (FC), chemical oxygen demand (COD) …

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No Tillage Use For Crop Production In Kentucky Counties In 1997, G. R. Haszler Jan 1998

No Tillage Use For Crop Production In Kentucky Counties In 1997, G. R. Haszler

Soil Science News and Views

Three years ago (1994) and again last year (1996), we reported the status of no-tillage adoption in Kentucky counties. Now, CTIC has published the results for 1997. As before, Kentucky leads the nation in percent of all crops produced under no tillage, but the percentage has slightly decreased from 1996. In 1994, 44% of all crops were produced under no tillage in Kentucky, whereas in 1996, that figure had reached 51% . It dropped to 48% in 1997. The results for 1994, 1996 and 1997 are shown in Table 1. The percentage of major grain crops (corn, soybeans and small …

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Precision Agriculture: A Field Study Of Soil Test Variability And Its Effect On Accuracy Of Fertilizer Recommendations, Kenneth L. Wells, James E. Dollarhide Jan 1998

Precision Agriculture: A Field Study Of Soil Test Variability And Its Effect On Accuracy Of Fertilizer Recommendations, Kenneth L. Wells, James E. Dollarhide

Soil Science News and Views

Use of precision agriculture techniques in Kentucky during the past several years has generated interest in how to soil sample a field for use in programming computer-driven, on-the-go, variable rate fertilizer spreaders (VRS). The advantage achieved by VRS is related directly to variability of soil test (ST) values within a specific field and the accuracy of how they represent the field. Since variability of ST values commonly exists on a small scale, a very intensive sampling procedure (grids of one acre or less in size) would be required to accurately describe the nature and extent of such variability within a …

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Precision Agriculture: The Effect Of Variable Rate Fertilizer Application On Soil Test Values, Kenneth L. Wells, James E. Dollarhide Jan 1998

Precision Agriculture: The Effect Of Variable Rate Fertilizer Application On Soil Test Values, Kenneth L. Wells, James E. Dollarhide

Soil Science News and Views

Use of variable rate fertilizer spreaders (VRS) is available to farmers in many areas of Kentucky. For use of VRS, a soil fertility map must be prepared for the field to be spread which requires subdividing the field into subunits. Each subunit is then soil sampled separately. A common procedure in commercial use is to grid a field into 2.5 acre blocks and to take a composite sample of 6-8 cores along the perimeter of a circular radius of 60-80 ft from the center of each block. Each block receives a separate fertilizer recommendation based on results from the soil …

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Late Season Supplemental Nitrogen On Double-Cropped Soybeans, Curt Judy, Lloyd W. Murdock Jan 1998

Late Season Supplemental Nitrogen On Double-Cropped Soybeans, Curt Judy, Lloyd W. Murdock

Soil Science News and Views

Soybeans produce their own nitrogen for crop growth with the aid of nitrogen fixing bacteria in the soil that infect the soybean root and form nodules which contain the bacteria. This is a symbiotic relationship that benefits both the plant and the bacteria. The bacteria are able to take atmospheric nitrogen and convert it into a form of nitrogen that the plant can use. Much of the nitrogen requirement for soybean production begins at seed development. Soybean physiology studies suggest that the amount of nitrogen supplied for the soybean plant from fixation in the nodules is less than the potential …

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A Two Year Evaluation Of Nitrate-N And Triazine Herbicides In Groundwater And Surface Water Of An Intensively Row Cropped Agricultural Watershed In Western Kentucky, Larry Reber, John Potts Jan 1998

A Two Year Evaluation Of Nitrate-N And Triazine Herbicides In Groundwater And Surface Water Of An Intensively Row Cropped Agricultural Watershed In Western Kentucky, Larry Reber, John Potts

Soil Science News and Views

The quality of water in Kentucky's agricultural watersheds has received considerable attention in recent years. The main concerns in corn production areas usually center on water content of nitrate-N from commercial fertilizer and triazines from herbicide applications. Although N can be found naturally in Kentucky soils, it cannot supply all the N that corn needs to produce optimum yields. Therefore, fertilizer N is added to ensure ample nutrition. Triazines, on the other hand, do not occur naturally in the soil but are applied to the soil to effectively control weeds. Most commonly, these herbicides are applied at the time of …

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Validating A Vegetative Filter Strip Performance Model, Puneet Srivastava, Thomas A. Costello, Dwayne R. Edwards, James A. Ferguson Jan 1998

Validating A Vegetative Filter Strip Performance Model, Puneet Srivastava, Thomas A. Costello, Dwayne R. Edwards, James A. Ferguson

Biosystems and Agricultural Engineering Faculty Publications

Vegetative filter strips (VFS) reduce losses of nutrients, solids, and other materials from land area treated with fertilizers and manures. A number of models are available that simulate nutrient and sediment transport in VFS. While VFS effectiveness is considered to depend on lengths of pollutant source area and VFS areas, few published studies have tried to validate these models using variable pollutant source area and VFS area. The objective of this study was to validate an event-based nutrient transport model (Chaubey et al., 1995) that simulates soluble nutrient transport in VFS. This model links three sub-models: modified Green-Ampt infiltration, non-linear …

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Use Of Animal Wastes On Cropland, Monroe Rasnake, M. Scott Smith Jan 1998

Use Of Animal Wastes On Cropland, Monroe Rasnake, M. Scott Smith

Soil Science News and Views

In recent months, environmental issues relating to land application of animal and industrial wastes have been widely debated in Kentucky. On several occasions, members of the University of Kentucky Agronomy Department have been asked to provide scientific information and technical interpretation related to these complex and controversial issues. To be certain that the public and policy makers are provided with consistent and scientifically sound information, the Agronomy Department has decided to release consensus statements on some of the major agronomic issues involved. These statements reflect our best scientifically based interpretations of these important subjects. Several of our faculty with long …

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Solute And Bacterial Transport Through Partially-Saturated Intact Soil Blocks, Edmund Perfect, Mark S. Coyne, Michael C. Sukop, Gerald R. Haszler, Virgil L. Quisenberry, Ligia Bejat Jan 1998

Solute And Bacterial Transport Through Partially-Saturated Intact Soil Blocks, Edmund Perfect, Mark S. Coyne, Michael C. Sukop, Gerald R. Haszler, Virgil L. Quisenberry, Ligia Bejat

KWRRI Research Reports

Steady-state transport of water, chloride and bacteria was measured through intact blocks of Maury and Cecil soils, under partially saturated conditions. Major objectives were to determine if transport occurs uniformly or via preferential flow paths, and if soil physical properties could be used to predict breakthrough. The blocks were instrumented with TDR probes and mounted on a vacuum chamber containing 100 cells that collected eflluent. After each experiment the blocks were sampled for soil physical properties. The fluxes showed no spatial autocorrelation and the eflluent variance was not statistically different between soils. Less than 3% of the influent bacteria appeared …

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