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Articles 15391 - 15420 of 15582

Full-Text Articles in Life Sciences

Eastern Black Nightshade, L. G. Rodrigue, W. W. Witt, Charles H. Slack, J. R. Martin Apr 1982

Eastern Black Nightshade, L. G. Rodrigue, W. W. Witt, Charles H. Slack, J. R. Martin

Agronomy Notes

The nightshade species of North America consist of black nightshade (Solanum nigrum L.), American black nightshade (Solanum americanum Mill.), hairy nightshade (Solanum surrachoides Sendt.) and eastern black nightshade (Solanum ptycanthum Dun.). Eastern black nightshade is a problem weed in many soybean producing areas and is the predominant problem nightshade in Kentucky. In addition to field crops, the nightshades are also problem weeds in canning peas (Pisum sativum L.), field beans (Phaseolus vulgaris L.), potatoes (Solanum tuberosum L.) and tomatoes (Lycopersicon esculentum Mill.). Previously, most nightshades in Kentucky have been referred to as black nightshade. It is now known that black …


Comparative Effectiveness Of Urea, Ammonium Nitrate, And Urea Ammonium Polyphosphate On Fescue Production, Lloyd W. Murdock Apr 1982

Comparative Effectiveness Of Urea, Ammonium Nitrate, And Urea Ammonium Polyphosphate On Fescue Production, Lloyd W. Murdock

Agronomy Notes

In the past, nitrogen (N) fertilizers used on grass pastures in Kentucky have largely been ammoniated phosphates in mixed fertilizers and ammonium nitrate. Due to the economic advantage of producing solid urea as opposed to ammonium nitrate, availability of urea is becoming greater and, in some areas, is the only source of solid nitrogen. If urea is not incorporated into the soil immediately after application, some of the nitrogen may be lost as ammonia gas. The loss is called volatilization. The amount of loss depends on a number of conditions. High soil and air temperatures and a moist soil which …


The Aquatic Toxicity Of Organic Compounds To Embryo-Larval Stages Of Fish And Amphibians, Jeffrey A. Black, Wesley J. Birge, Willaim E. Mcdonnell, Albert G. Westerman, Barbara A. Ramey, Donald M. Bruser Mar 1982

The Aquatic Toxicity Of Organic Compounds To Embryo-Larval Stages Of Fish And Amphibians, Jeffrey A. Black, Wesley J. Birge, Willaim E. Mcdonnell, Albert G. Westerman, Barbara A. Ramey, Donald M. Bruser

KWRRI Research Reports

Aquatic toxicity tests were conducted on 11 organic compounds considered hazardous to water resources. The toxicity of each compound was evaluated using embryo-larval stages of two to eight fish and amphibian species. Exposure was initiated at fertilization and maintained through 4 days posthatching. The animal test species exhibited varying degrees of sensitivity to the selected toxicants. Combined frequencies for mortality and teratogenesis at 4 days posthatching gave LC50 ranges of 3.66 to 8.25 mg/L for benzene, 1.16 to 22.42 mg/L for carbon tetrachloride, 0.11 to 1.20 mg/L for chlorobenzene, 2.03 to > 68 mg/L for chloroform, 3.01 to 5.56 mg/L …


Sunlight Induced Movement Of Planktonic Organisms And Their Relationships To Water Movements, John Calkins, Ed Colley, Jay Wallingford, Carol Hulsey, Kathy Lohr, Marc Bolling Mar 1982

Sunlight Induced Movement Of Planktonic Organisms And Their Relationships To Water Movements, John Calkins, Ed Colley, Jay Wallingford, Carol Hulsey, Kathy Lohr, Marc Bolling

KWRRI Research Reports

Previous studies have shown the planktonic organisms of various natural water bodies to be quite sensitive to the levels of solar ultraviolet radiation incident at the water surface in summer. It has been assumed that the majority of the phytoplankton are simply carried about in the mass of the water which they inhabit with little control of their position or sunlight exposure. Photosynthetic microorganisms must strike a delicate balance with regard to solar radiation; they must obtain enough visible light for adequate photosynthesis while avoiding an excessive exposure to the injurious solar UV-B radiation.

It is proposed that the circulation …


Alfalfa, White Clover, And Red Clover Variety Trials, Roy E. Sigafus, Norman L. Taylor, Garry D. Lacefield, J. Kenneth Evans Feb 1982

Alfalfa, White Clover, And Red Clover Variety Trials, Roy E. Sigafus, Norman L. Taylor, Garry D. Lacefield, J. Kenneth Evans

Agronomy Notes

This note is a brief summary of results obtained in 1981 from one white clover, five alfalfa, and three red clover trials. Yields in the seeding year, and from the first full year of production thereafter, are not the best estimate of the full potential of most forage legumes. The third season stand and yield are a good measure of persistency with red clover and white clover. At times it may be the fourth or fifth season with alfalfa before stands begin to thin.

To supply information on the best varieties available there is a continuous monitoring of new varieties …


Effect Of Herbicides On Performance Of Aerobic Dairy Lagoons, John D. Bottom, Joseph L. Taraba Jan 1982

Effect Of Herbicides On Performance Of Aerobic Dairy Lagoons, John D. Bottom, Joseph L. Taraba

Biosystems and Agricultural Engineering Faculty Publications

The herbicides glyphosate, bromacil, and dalapon were assessed for their affect on the oxygen uptake of microorganisms from an aerated dairy lagoon at 20 °C. The maximum recommended addition of herbicide active ingerdient to a lagoon is: glyphosate (isopropyl amino salt)—0.42 mg/L; bromacil—3.70 mg/L; and dalapon (85.8 percent Na salt and 14.2 percent Mg salt)—1.95 mg/L. In addition, microorganism isolates from the aerobic dairy lagoon were incubated under aerobic and anerobic conditions at room temperature to assess the effects of the herbicides. Under aerobic incubation, it was found that neither herbicide type nor herbicide concentration affected isolate growth. Under anaerobic …


Vertical Wall Loads In A Model Grain Bin, S. A. Thompson, I. J. Ross, John N. Walker, Larry G. Wells Jan 1982

Vertical Wall Loads In A Model Grain Bin, S. A. Thompson, I. J. Ross, John N. Walker, Larry G. Wells

Biosystems and Agricultural Engineering Faculty Publications

No abstract provided.


Temperature And Humidity Prediction In A Burley Curing Facility, Thomas C. Bridges, Linus R. Walton, Larry G. Wells, I. J. Ross Jan 1982

Temperature And Humidity Prediction In A Burley Curing Facility, Thomas C. Bridges, Linus R. Walton, Larry G. Wells, I. J. Ross

Biosystems and Agricultural Engineering Faculty Publications

No abstract provided.


Simulation Of Burley Tobacco Harvesting-Housing Systems, Ronald L. Bingner, Larry G. Wells, Thomas C. Bridges, George A. Duncan Jan 1982

Simulation Of Burley Tobacco Harvesting-Housing Systems, Ronald L. Bingner, Larry G. Wells, Thomas C. Bridges, George A. Duncan

Biosystems and Agricultural Engineering Faculty Publications

A computer model has been developed using systems analysis techniques to simulate the labor and equipment aspects of harvesting burley tobacco. By varying the parameters of the model the user can determine a harvesting and housing strategy based on labor and equipment availability.


Use Of Molybdenum In The Transplant Water For Burley Tobacco, J. L. Sims, Jones H. Smiley, M. E. Suchy, A. M. Wallace May 1981

Use Of Molybdenum In The Transplant Water For Burley Tobacco, J. L. Sims, Jones H. Smiley, M. E. Suchy, A. M. Wallace

Agronomy Notes

The need for adding molybdenum to tobacco arises because contents in Kentucky soils generally are on the "borderline" of sufficiency and because amounts of available molybdenum in soil are low when soil pH is low. Soil pH in tobacco fields at midseason often is 0.5 to 1.0 pH unit lower than prior to fertilization. primarily because of the high rates of commercial fertilizers commonly applied to tobacco. This acidity greatly lowers the availability of molybdenum to tobacco plants. That is why we recommend the use of molybdenum when soil pH before fertilization is 6.4 or below.


Efficient Pasture Systems, J. Kenneth Evans, Garry D. Lacefield Feb 1981

Efficient Pasture Systems, J. Kenneth Evans, Garry D. Lacefield

Agriculture and Natural Resources Publications

The manner in which a pasture is grazed will have a marked influence on pasture productivity. persistence. quality and animal performance. Very light grazing pressure (few animals per unit area) results in high production per animal because animals can graze selectively. Low production per acre will be obtained because forage is wasted. Very heavy grazing pressure {many animals per unit area) may force animals to consume low quality plants or plant parts. If this occurs for very long. production per animal will be low. but production per acre may be increased because little forage is wasted. Also. persistence of desirable …


Correction And Prevention Of Soil Compaction, Lloyd W. Murdock Feb 1981

Correction And Prevention Of Soil Compaction, Lloyd W. Murdock

Agronomy Notes

Soil can be compacted by both natural and man made forces. The most common cause results from tillage practices. These man induced compacted layers are often called a traffic pan, disc pan, plow pan, wheel compaction, hard pan, etc. Some compaction occurs in most soils that are tilled. If compaction is Severe enough, it may reduce plant growth and yield. Soil compaction can be corrected by subsoiling and deep plowing but they are expensive methods. Soil compaction may not be a problem if one understands compaction, its effects, and how to prevent it.


Simulating The Water Requirements And Economic Feasibility Of Corn In The Midwest, Wendi L. Palmer, B. J. Barfield, M. E. Bitzer, C. T. Haan Jan 1981

Simulating The Water Requirements And Economic Feasibility Of Corn In The Midwest, Wendi L. Palmer, B. J. Barfield, M. E. Bitzer, C. T. Haan

KWRRI Research Reports

An evaluation of the economics of supplemental irrigation when using a surface water supply must be site specific in order to account for variations in soil moisture holding capacity, watershed area supplying the runoff, climatic conditions, and proposed irrigation management procedures.

With the use of farm specific simulation models to determine grain yields, availability of irrigation water, and economic expenditures involved in irrigation, an economic evaluation of supplemental irrigation can be performed, In the model presented in this report, the Duncan SIMAIZ model is used to predict grain yields using long-term daily weather information. SIMAIZ also determines irrigation water demand …


A Simulation Model For Assessing Alternate Strategies For Beef Production With Land, Energy And Economic Constraints, Otto J. Loewer, E. M. Smith, G. Benock, Thomas C. Bridges, Larry G. Wells, Nelson Gay, S. Burgess, L. Springate, David L. Debertin Jan 1981

A Simulation Model For Assessing Alternate Strategies For Beef Production With Land, Energy And Economic Constraints, Otto J. Loewer, E. M. Smith, G. Benock, Thomas C. Bridges, Larry G. Wells, Nelson Gay, S. Burgess, L. Springate, David L. Debertin

Biosystems and Agricultural Engineering Faculty Publications

A computer model has been developed to analyze alternate management strategies and energy and economic constraints. Daily production of beef animals and growing crops is simulated in response to prevailing conditions and system interactions using the GASP IV simulation language. Complete inventories of plant dry matter, animal status, production resources and economic net worth are maintained over the simulation period.


Slope Stabilization With Crown Vetch, A. J. Powell Jr. Jun 1980

Slope Stabilization With Crown Vetch, A. J. Powell Jr.

Agriculture and Natural Resources Publications

Once established, crown vetch provides an excellent, almost maintenance-free, cover for soil stabilization and slope beautification. It grows approximately two feet tall and blooms from June through September, producing pink to pinkish-purple flowers. Crown vetch is strongly rhizomatous (underground root stalks) and grows well on clay textured and shallow soils. It is highly recommended for low maintenance areas such as slopes around commercial or public buildings, highway and/or driveway slopes, lawn areas too steep for safe mowing and slopes associated with many recreational facilities or parks.


Corn Yields From Fertilizer Recommendations Made By Some Soil Testing Laboratories Serving Kentucky, Lloyd W. Murdock, William Hendrick Jun 1980

Corn Yields From Fertilizer Recommendations Made By Some Soil Testing Laboratories Serving Kentucky, Lloyd W. Murdock, William Hendrick

Agronomy Notes

One of the most economically important services available to Kentucky farmers is that of soil testing and fertilizer recommendations. Fertilizer purchases on the order of 150 million dollars per year are currently made by farmers in Kentucky. Until about 30 years ago there was no routine, rapid method for analyzing soils to determine fertilizer needs. Since then, as better methods were developed, soil testing laboratories have been set up for routine farmer use. For many years only the soil testing service provided through the University of Kentucky (UK) was readily available to farmers in Kentucky. Even though the University still …


A Cropping System For Intensive Grain Production On Sloping Land, Kenneth L. Wells, H. C. Vaught, Morris J. Bitzer, M. W. Russell Mar 1980

A Cropping System For Intensive Grain Production On Sloping Land, Kenneth L. Wells, H. C. Vaught, Morris J. Bitzer, M. W. Russell

Agronomy Notes

From the beginnings of Kentucky Agriculture, soil erosion and related losses in productivity have been major problems for Kentucky farmers. Improved soil conservation practices during the past forty years have been especially significant in the recovery and progress of our agricultural industry. No-tillage methods for crop production, which were pioneered in Kentucky, have proven useful in controlling erosion and holding production at high levels. During recent years, the marketplace has strongly encouraged grain production, with the unfortunate effect that many Kentucky hillsides have been returned to grain production without sufficient erosion control measures. This report describes innovations in use of …


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 …


Analysis And Testing Of Powered Tillage Blades, Larry G. Wells, E. M. Smith, D. E. Hammett Jan 1980

Analysis And Testing Of Powered Tillage Blades, Larry G. Wells, E. M. Smith, D. E. Hammett

Biosystems and Agricultural Engineering Faculty Publications

Fundamental design considerations for powered rotary tillage blades are presented and discussed. The relationship between blade angular velocity and the geometric dimensions of cutting edges is specified for tillage blades rotating counter to the direction of travel and assuming a typical forward speed for tillage.

Analyses showed that a powered blade rotated opposite to the direction of travel can be operated at relatively lower angular velocities than can one rotated in the direction of travel to achieve equivalent blade velocity and acceleration relative to the soil. Furthermore, a blade rotated opposite to the direction of travel requires relatively lower power …


Dynamic Simulation Of Animal Growth And Reproduction, Otto J. Loewer Jr., Edward M. Smith, Gerald Benock, Nelson Gay, Thomas C. Bridges, Larry G. Wells Jan 1980

Dynamic Simulation Of Animal Growth And Reproduction, Otto J. Loewer Jr., Edward M. Smith, Gerald Benock, Nelson Gay, Thomas C. Bridges, Larry G. Wells

Biosystems and Agricultural Engineering Faculty Publications

A rather unique systems analysis approach has been made to simulate the utilization of dry matter by ruminant animals, and the natural breeding and reproduction process within a herd. Physiological factors occurring over time and the time related effects of these factors are simulated.


Wind Drag On Burley Tobacco Plants, James H. Casada, Linus R. Walton, Larry G. Wells Jan 1980

Wind Drag On Burley Tobacco Plants, James H. Casada, Linus R. Walton, Larry G. Wells

Biosystems and Agricultural Engineering Faculty Publications

Drag coefficient and center of resistance to wind forces were determined for four varieties of burley tobacco at three stages of growth and using wind velocities ranging from about 3 to 17 m/s. Drag coefficients determined ranged from about 0.024 at the highest velocity to about 0.081 at the lowest velocity. Stage of growth and wind velocity had significant effects on drag coefficient. Variety did not have a significant effect on drag coefficient. Mean center of resistance varied from 42.3 percent of the distance from bottom leaf to top leaf at the early stage of growth to 71.2 percent at …


Horse Pasture, Garry D. Lacefield, J. Kenneth Evans, John P. Baker Jan 1980

Horse Pasture, Garry D. Lacefield, J. Kenneth Evans, John P. Baker

Agriculture and Natural Resources Publications

Pastures for horses should be more than mere exercise lots. High quality pasture can supply enough protein, vitamins, and minerals to meet the nutritional needs of most pleasure horses at relatively low cost. Although pastures furnish substantial amounts of energy, working horses will likely need additional energy supplementation. In addition, pasture will help to maintain healthy animals by furnishing the bulk needed in horse rations, as well as exercise areas, sunshine, and fresh air.

The pasture should be enclosed by a safe, strong fence. Fresh water and shade should also be provided. The pasture should be large enough to encourage …


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 …


The Influence Of Harvesting Strategies And Economic Constraints On The Feasibility Of Farm Grain Drying And Storage Facilities, Otto J. Loewer Jr., Thomas C. Bridges, G. M. White, Douglas G. Overhults Jan 1980

The Influence Of Harvesting Strategies And Economic Constraints On The Feasibility Of Farm Grain Drying And Storage Facilities, Otto J. Loewer Jr., Thomas C. Bridges, G. M. White, Douglas G. Overhults

Biosystems and Agricultural Engineering Faculty Publications

The economic return to on-the-farm grain drying and storage facilities is influenced by many factors including harvesting strategies, facility management, market conditions, energy considerations, and facility design. This study evaluates the influence of these factors on expected net return.


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.


Establishment Of Football Turf, A. J. Powell Jr. Mar 1979

Establishment Of Football Turf, A. J. Powell Jr.

Agriculture and Natural Resources Publications

Turf on all athletic fields should provide playing safety, good footing, and a pleasing appearance. It should be resilient enough to cushion falls and prevent abrasions, but also firm enough to permit good surface stability. In order to establish a quality field, proper construction and establishment are necessary. There are many construction techniques used in building athletic fields, depending upon available capital and intended use. The following would be considered minimum recommendations.


Soybean Inoculant Quality, J. L. Sims, E. C. Lacefield, Lloyd W. Murdock Feb 1979

Soybean Inoculant Quality, J. L. Sims, E. C. Lacefield, Lloyd W. Murdock

Agronomy Notes

Research studies have shown that from 40 to 80 percent of the nitrogen required for a soybean crop comes from nitrogen fixed in the nodules, depending on the degree of nodulation and the level of soil nitrogen. Hence, it is important that soybean plants be well-nodulated for most efficient soybean production.


Effect Of Lime On No-Tillage Corn Yields, Robert L. Blevins, Lloyd W. Murdock Feb 1979

Effect Of Lime On No-Tillage Corn Yields, Robert L. Blevins, Lloyd W. Murdock

Agronomy Notes

The rapidly growing popularity and adoption of no-tillage systems of corn production have required us to re-evaluate some of our long established soil fertility practices and recommendations. Recent work by researchers at Kentucky and adjacent states show that the soil surface becomes very acid after a few years of continuous no-tillage corn production. This rapid decrease in soil pH is primarily associated with surface application of nitrogen fertilizers. Most lime recommendations and related research information for row crop production are based on plow-down application. Therefore, the effectiveness of surface-applied and unincorporated lime under no-tillage systems becomes a question of concern. …


The Influence Of Harvest Rate And Drying Time On Grain Drying And Storage Facility Selection, Thomas C. Bridges, Otto J. Loewer Jr., Douglas G. Overhults Jan 1979

The Influence Of Harvest Rate And Drying Time On Grain Drying And Storage Facility Selection, Thomas C. Bridges, Otto J. Loewer Jr., Douglas G. Overhults

Biosystems and Agricultural Engineering Faculty Publications

No abstract provided.


Determination Of Strategy For Harvesting Burley Tobacco, Yasuhiko Miyake, Larry G. Wells, George A. Duncan, Jimmie Rankin Jan 1979

Determination Of Strategy For Harvesting Burley Tobacco, Yasuhiko Miyake, Larry G. Wells, George A. Duncan, Jimmie Rankin

Biosystems and Agricultural Engineering Faculty Publications

The decision-making process associated with the scheduling of burley tobacco harvesting operations was formulated as a multi-stage decision process, and solved using a procedure called dynamic programming. The solution of a stochastic dynamic programming model provides a set of optimal decision rules, that is, a strategy. When certain user-specified parameters are provided, the decision model provides information concerning the optimal date to start harvesting, the optimal number of hours to harvest on each day, the optimal date to introduce hired labor, and the optimal number of workers which should be hired.

The solution of the dynamic programming model makes it …