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Full-Text Articles in Physical Sciences and Mathematics

Fertilizer Recommendations, William O. Thom Dec 1980

Fertilizer Recommendations, William O. Thom

Soil Science News and Views

Fertilizer recommendations are interpreted from a soil test value. The interpretations are based on field research that compares crop yield to soil test levels and the amount of fertilizer applied. These field studies provide data to compare relative yield of a crop for a measured soil test value and fertilizer recommendations are then calibrated to these soil test values.


Soil Drainage---Effects On Crop Production, Kenneth L. Wells Nov 1980

Soil Drainage---Effects On Crop Production, Kenneth L. Wells

Soil Science News and Views

One of the major physical properties of soil which is important to crop production is drainage through the rooting zone. This characteristic greatly influences aeration in the rooting zone, and the degree of aeration greatly influences several important biochemical reactions of economic importance to crop production.


Conservation Tillage Practices, Monroe Rasnake Oct 1980

Conservation Tillage Practices, Monroe Rasnake

Soil Science News and Views

The loss of topsoil from farmlands has become a serious problem in some parts of Kentucky. During the past 20 years, grain crop acreage has tripled. The production of soybeans, which leaves the soil in a condition more susceptible to erosion, has grown from almost none to 1.7 million acres. Much of this increased acreage has come at the expense of soil conserving crops such as hay and pasture on sloping class II and III land with an erosion hazard. Use of large equipment, larger fields, chemical weed control, etc., has added to the scope of the problem with which …


Use Of Annual Legumes As Winter Cover For No-Till Corn, Robert L. Blevins Sep 1980

Use Of Annual Legumes As Winter Cover For No-Till Corn, Robert L. Blevins

Soil Science News and Views

Legumes in crop rotations hsve traditionally provided nitrogen for nonlegume crops since the early history of agriculture. When in association with the proper strains of Rhyzobium bacteria, legumes are capable of fixing atmospheric nitrogen, which when residues from the legumes decompose, enrich the soil content of nitrogen. Legume cover crops recycle other nutrients, thus reducing leaching losses that often occur in soils during the winter and spring seasons. In addition to these advantages, legume cover crops used with no-tillage corn provide a surface mulch which reduces soil erosion, slows evaporation of soil moisture, increases infiltration of rainfall, and increases soil …


Effects Of Soil Erosion On Productivity, Wilbur Frye Jul 1980

Effects Of Soil Erosion On Productivity, Wilbur Frye

Soil Science News and Views

About 75 percent of Kentucky's agricultural land is sloping enough that potential erosion losses must be considered in its management. In addition to the effect of soil erosion on water pollution is the question of its effect on the productivity of the soil. This is a complex question due to the interactions of the many factors that affect crop growth. Furthermore, the same degree of erosion has a greater adverse effect on some soils than on others. The kind of erosion that has taken place or is taking place is a major factor in making land use decisions for crop …


Delayed Nitrogen Applications On Corn, Grant W. Thomas Jun 1980

Delayed Nitrogen Applications On Corn, Grant W. Thomas

Soil Science News and Views

A method of fertilizer application that was standard practice 30 to 50 years ago has become important once again, and for the same reason. When nitrogen fertilizer was expensive and corn was cheap, it was considered prudent to save back some of the nitrogen fertilizer and apply it when the corn was "knee-high." This was thought to be safer because some of the nitrogen added at planting might be lost before the corn was big enough to take advantage of it. The increasing cost of nitrogen fertilizer has made efficient use of this product important again.


Soybean Inoculation, J. L. Sims May 1980

Soybean Inoculation, J. L. Sims

Soil Science News and Views

Well-nodulated soybean plants are needed for most efficient soybean production. Recent research by University of Kentucky Agronomy Department personnel indicated that on Maury soil without N fertilizer, nodulating plant types of Clark 63 variety yielded 8 bushels per acre more than the non-nodulating Clark 63. With application of 125 lbs N per acre to the non-nodulating type only, both types yielded the same, showing the value of good nodulation.


An Avoidance Response Bioassay For Aquatic Pollutants, Jeffrey A. Black, Wesley J. Birge Apr 1980

An Avoidance Response Bioassay For Aquatic Pollutants, Jeffrey A. Black, Wesley J. Birge

KWRRI Research Reports

Avoidance response bioassays were conducted with eight aquatic contaminants, including cadmium, copper, mercury, zinc, chloroform, dioctyl phthalate (DOP), trisodium nitrilotriacetic acid (NTA), and phenol. Tests were performed in a dual-channel fluviarium system, and the toxicant injection procedure used provided good regulation of exposure concentrations. Juvenile stages of largemouth bass (Micropterus salmoides), bluegill sunfish (Lepomis macrochirus), and rainbow trout (Salmo gairdneri), and tadpoles of the American toad (Bufo americanus) proved to be suitable animals for evaluating avoidance or attraction responses. The trout was the most sensitive species tested.

Avoidance was significant in tests …


Determination Of Sediment Filtration Efficiency Of Grass Media, David T. Kao Mar 1980

Determination Of Sediment Filtration Efficiency Of Grass Media, David T. Kao

KWRRI Research Reports

Vegetative filters serve the purpose of retarding flow. As a result the sediment carrying power of flowing water in a vegetated channel is greatly reduced and silting takes place along the section where the vegetation is planted.

The mechanism of the filtering action of real or artificial vegetation can be described by a simplified principle, in that a gross reduction of turbulent fluctuation of the fluid is involved. This in turn allows the sediment particles to settle under the force of gravity more readily. In the case of nonsubrnerged flow, solid particles may settle out even faster due to the …


An Environmental Study Of The Origin, Distribution, And Bioaccumulation Of Selenium In Kentucky And Barkley Lakes, B. E. Mcclellan, Kenneth J. Frazer Feb 1980

An Environmental Study Of The Origin, Distribution, And Bioaccumulation Of Selenium In Kentucky And Barkley Lakes, B. E. Mcclellan, Kenneth J. Frazer

KWRRI Research Reports

Many samples of water, bottom sediment, and fish were analyzed for toxic metal ion content. The samples were collected from several selected sites along Kentucky and Barkley Lakes as well as the Cumberland River and several sub-impoundments along these aquatic systems. Emphasis was placed on selenium, although several other metal ions were determined. The results showed that there are no serious pollution problems with As, Cd, Cr, Cu, Hg, Pb, Se, Sr, Zn, or Zr at any of the sites examined. Actually, none of the trace metals examined even come close to the EPA limits on fish, with the exception …


High-Carbonate And Low-Silica Stone In The High Bridge Group (Middle Ordovician), Fayette County, Central Kentucky, Garland R. Dever Jr. Jan 1980

High-Carbonate And Low-Silica Stone In The High Bridge Group (Middle Ordovician), Fayette County, Central Kentucky, Garland R. Dever Jr.

Information Circular--KGS

The High Bridge Group (Middle Ordovician) of central Kentucky, a major source of limestone and dolomite for construction and agricultural stone, is also a potential source of stone for industrial uses requiring carbonate rocks of high chemical purity. Chemical analyses of foot-by-foot samples from a Fayette County core show that several thick zones of high-carbonate and low-silica stone are present in the High Bridge at a minable depth.


Bibliography Of The Kentucky Geological Survey, 1839 Through 1978, Kentucky Geological Survey Jan 1980

Bibliography Of The Kentucky Geological Survey, 1839 Through 1978, Kentucky Geological Survey

Information Circular--KGS

It is the hope of the authors that all of the various publications and maps of the Kentucky Geological Survey are included in this bibliography. It is our intent to revise, supplement, and update the publication lists in "Geological Research in Kentucky" by Willard Rouse Jillson (1923).

During its history the Kentucky Geological Survey has suffered losses from two disastrous fires, one at Frankfort in 1929, and a second at Lexington in 1948. Many maps and some of the reports were reprinted after 1948 in Series VIII, but so many of the earlier publications were lost that they are now …


Ground Driven Powered Tillage, Larry G. Wells, E. M. Smith, D. E. Hammett, H. J. Thompson Jr. Jan 1980

Ground Driven Powered Tillage, Larry G. Wells, E. M. Smith, D. E. Hammett, H. J. Thompson Jr.

Biosystems and Agricultural Engineering Faculty Publications

A ground driven powered tillage device is described which utilizes a passive rolling coulter propelled through the soil by a prime mover. The reaction torque imparted by the soil to the coulter is delivered via a torque transfer unit to a powered tillage blade. The tillage blade rotates counter to the direction of the passive rolling coulter and prepares a tilled furrow of some predetermined depth for seed placement and coverage.

Analysis is presented in which the torque developed by a passive rolling coulter engaging the soil is predicted. A relationship is presented for determining the velocity ratio between the …


Economic Comparison Of Alternative Burley Tobacco Harvesting Practices By Computer, Thomas C. Bridges, Larry G. Wells, George A. Duncan, John N. Walker Jan 1980

Economic Comparison Of Alternative Burley Tobacco Harvesting Practices By Computer, Thomas C. Bridges, Larry G. Wells, George A. Duncan, John N. Walker

Biosystems and Agricultural Engineering Faculty Publications

The computer model CATCH (Computer Analysis of Tobacco Cutting and Housing) was developed to provide the individual tobacco producer with management information concerning alternative methods of harvesting burley tobacco. CATCH utilizes specific producer in-puts to analyze 24 alternative burley production systems and presents up to four economic rankings containing costs, equipment and labor for each system. The economic rankings aid the producer in decision making with regard to his own operation.


Effects Of Organic Compounds On Amphibian Reproduction, Wesley J. Birge, Jeffrey A. Black, Robert A. Kuehne Jan 1980

Effects Of Organic Compounds On Amphibian Reproduction, Wesley J. Birge, Jeffrey A. Black, Robert A. Kuehne

KWRRI Research Reports

Aquatic toxicity tests were conducted with atrazine, carbon tetrachloride, chloroform, methylene chloride, trisodium nitrilotriacetic acid (NTA), and phenol. Each compound was administered to developmental stages of three to five amphibian species. Exposure was initiated at fertilization and maintained through 4 days posthatching. Test responses included lethality and teratogenesis. Different amphibian species exhibited varying degrees of tolerance to the selected compounds. Greatest tolerance usually was observed for the more broadly adapted semi-aquatic and terrestrial species (e.g., Bufo americanus, Bufo fowleri). The more sensitive amphibians usually included those species which normally are restricted to aquatic or moist habitats (e.g., Rana …