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Full-Text Articles in Physical Sciences and Mathematics

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 …


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 …


Kentucky's Coal Industry: Historical Trends And Future Opportunities, Gerald A. Weisenfluh, James C. Cobb, John C. Ferm, Carol L. Ruthven Jan 1998

Kentucky's Coal Industry: Historical Trends And Future Opportunities, Gerald A. Weisenfluh, James C. Cobb, John C. Ferm, Carol L. Ruthven

Information Circular--KGS

Coal has been produced in Kentucky since the late 18th century. In the early years, all mining was by underground methods, but surface mining became the dominant method during and after World War II. In recent years, surface-mine production in both fields has decreased while underground mining has increased.

In the last half of this century, the traditional steam coal market for locomotives has virtually disappeared, leaving electric power generation and coking coal for the steel industry as the principal markets. More than half of all coal produced in the State has been produced in the last 25 years. Whether …


Spatial And Temporal Variability In Seepage Between A Contaminated Aquifer And Tributaries To The Ohio River, Alan E. Fryar, David L. Brown, David B. Wenner, Todd C. Rasmussen, Eric J. Wallin Jan 1998

Spatial And Temporal Variability In Seepage Between A Contaminated Aquifer And Tributaries To The Ohio River, Alan E. Fryar, David L. Brown, David B. Wenner, Todd C. Rasmussen, Eric J. Wallin

KWRRI Research Reports

Because interactions between ground water and tributaries may influence contaminant loading to rivers, we delineated seepage along Little Bayou and Bayou Creeks in McCracken County, Kentucky, during a two-year period. From the Paducah Gaseous Diffusion Plant, on the divide between the creeks, trichloroethene and technetium-99 plumes extend several km toward the Ohio River. Gaining conditions occur where the creeks are incised into coarse sediments in the river's flood plain. Such conditions were marked by upward hydraulic gradients within the bed; maximum specific discharge (q) > 0.24 m d-1; relatively narrow ranges of stream, piezometer, and bed temperatures; relatively cool …


Mineral And Fuel Resources Map Of Kentucky, Warren H. Anderson, Garland R. Dever Jr. Jan 1998

Mineral And Fuel Resources Map Of Kentucky, Warren H. Anderson, Garland R. Dever Jr.

Map and Chart--KGS

The production of minerals and fuels in Kentucky is a multibillion dollar industry. Historically, coal, oil, natural gas, limestone, sand and gravel, clay, fluorite, barite, lead, iron, phosphate, zinc, and brines have been produced in the State. These resources have greatly influenced the development of Kentucky by providing raw materials for the early settlers who settled the State and for current industrial and economic development. Electrical power for homes, businesses, and factories; materials for constructing houses, buildings, automobiles, and roads; and products we consume in everyday life come from the earth's mineral and fuel resources.