Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons™

Open Access. Powered by Scholars. Published by Universities.®

University of Kentucky

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 15061 - 15090 of 15585

Full-Text Articles in Life Sciences

Early Maturing Varieties And Soybean Cyst Nematodes: Will This "Marriage" Work?, Colleen C. Steele, Larry J. Grabau Jan 1996

Early Maturing Varieties And Soybean Cyst Nematodes: Will This "Marriage" Work?, Colleen C. Steele, Larry J. Grabau

Agronomy Notes

Soybean cyst nematode (SCN) is widely distributed in Kentucky's soybean growing areas. The use of SCN-resistant varieties has long been a recommended production practice for infested fields. However, continuous use of such varieties can result in a shift to a race of SCN which is able to vigorously attack previously resistant varieties. For his reason, many states have long recommended that producers periodically grow a crop of SCN-susceptible soybeans within a crop rotation when SCN populations are too low to cause yield reductions. In Kentucky, the UK Plant Pathology Department recommends a four year rotation in SCN-infested fields [PPA3; "Wanted: …


Preliminary Maturity Group Ii Soybean Variety Trials, Colleen C. Steele, Larry J. Grabau Jan 1996

Preliminary Maturity Group Ii Soybean Variety Trials, Colleen C. Steele, Larry J. Grabau

Agronomy Notes

On-farm research with early maturing soybean varieties in Kentucky in both 1993 and 1994 has indicated that Maturity Group (MG) II varieties yield competitively with our traditional MG IV varieties. In those tests, four MG II varieties were compared with a single, high yielding MG IV variety (Asgrow A4715) over a range of planting dates on a total of 27 farms across both years. Asgrow A4715 averaged 43 bu/A, while the best MG II variety (Jack) averaged 39 bu/A. Such on-farm strip tests are valuable for comparing varieties under true production conditions. However, strip tests can effectively compare only a …


Differential Black Walnut Growth On A Recommended Soil Map Unit: Investigation Of Related Soil Chemical And Physical Properties, David C. Ditsch, Jeff Stringer, D. Mcintosh Jan 1996

Differential Black Walnut Growth On A Recommended Soil Map Unit: Investigation Of Related Soil Chemical And Physical Properties, David C. Ditsch, Jeff Stringer, D. Mcintosh

Agronomy Notes

Black walnut (Juglans nigra L.) is one of the best known and most valuable trees in Kentucky. However, due to its high value, the species has been aggressively harvested from natural stands, creating a limited supply of quality black walnut trees. Many landowners recognize this as an investment opportunity and have placed small tracts of unused land into black walnut production.


Als Resistant Smooth Pigweed In Western Kentucky, R. E. Schmenk, Michael Barrett, William W. Witt Jan 1996

Als Resistant Smooth Pigweed In Western Kentucky, R. E. Schmenk, Michael Barrett, William W. Witt

Agronomy Notes

Pigweeds The pigweed, or Amaranthus, family contains some of the most commonly occurring weeds of midwest agriculture. Species from this family that occur in Kentucky include smooth pigweed (Amaranthus hybridus, most common), tumble pigweed, prostrate pigweed, spiny amaranth,Palmer amaranth,common waterhemp, and tall waterhemp. Research has shown that some pigweed species respond differently to various herbicides, therefore, proper identification is necessary to achieve acceptable control. Pigweed identification in early stages of seedling growth can be difficult because the distinguishing physical characteristics do not appear until plants are mature or have produced seed. Also, some pigweed species may cross-pollinate to …


Effect Of Boron Fertilization On Alfalfa, Monroe Rasnake, Garry D. Lacefield Jan 1996

Effect Of Boron Fertilization On Alfalfa, Monroe Rasnake, Garry D. Lacefield

Agronomy Notes

The need for boron (B) fertilization of alfalfa has been known for many years. An annual application of 1.5 to 2.0 ·pounds of elemental B per acre on alfalfa has been the general recommendation of the University of Kentucky's, Department of Agronomy for at least 20 years. Most states surrounding Kentucky have similar recommendations; however, some indicate that B needs to be applied only once every two years. There has been very little recent research to verify the need for B on alfalfa.


Evaluation Of The Crop Growth Component Of The Root Zone Water Quality Model For Corn In Ohio, Sue E. Nokes, Feliks M. Landa, Jon D. Hanson Jan 1996

Evaluation Of The Crop Growth Component Of The Root Zone Water Quality Model For Corn In Ohio, Sue E. Nokes, Feliks M. Landa, Jon D. Hanson

Biosystems and Agricultural Engineering Faculty Publications

The Root Zone Water Quality Model (RZWQM) is a computer model developed to simulate water, chemical, and biological processes in the root zone of agricultural management systems. As of this writing RZWQM is in the beta-testing phase of development. This article reports on a parameterization and evaluation study performed in Ohio on field corn for the crop growth component of RZWQM. The generic crop growth model in RZWQM had not previously been parameterized or tested on field corn. This article reports the results of such a study. One year of data was used to calibrate RZWQM, and two additional years …


Comparison Of Daily Water Table Depth Prediction By Four Simulation Models, Eric D. Desmond, Andrew D. Ward, Norman R. Fausey, Stephen R. Workman Jan 1996

Comparison Of Daily Water Table Depth Prediction By Four Simulation Models, Eric D. Desmond, Andrew D. Ward, Norman R. Fausey, Stephen R. Workman

Biosystems and Agricultural Engineering Faculty Publications

The Agricultural Drainage And Pesticide Transport (ADAPT) model was compared to the water management simulation models DRAINMOD, SWATREN, and PREFLO. SWATREN and PREFLO are one-dimensional finite-difference models while ADAPT and DRAINMOD are one-dimensional mass balance models. ADAPT, an extension of the computer model GLEAMS, also provides chemical transport information. All four models were tested against field data from Aurora, North Carolina. Observed water table depth data were collected during 1973 through 1977 from a water table management field experiment with three subsurface drain spacing treatments of 7.5, 15, and 30 m.

Both the standard error of estimate and the average …


Performance Of Vegetative Filter Strips With Varying Pollutant Source And Filter Strip Lengths, Puneet Srivastava, Dwayne R. Edwards, Tommy C. Daniel, Philip A. Moore Jr., Thomas A. Costello Jan 1996

Performance Of Vegetative Filter Strips With Varying Pollutant Source And Filter Strip Lengths, Puneet Srivastava, Dwayne R. Edwards, Tommy C. Daniel, Philip A. Moore Jr., Thomas A. Costello

Biosystems and Agricultural Engineering Faculty Publications

Vegetative filter strips (VFS) can reduce runoff losses of pollutants such as nitrogen (N) and phosphorus (P) from land areas treated with fertilizers. While VFS effectiveness is considered to depend on lengths of pollutant source and VFS areas, there is little experimental evidence of this dependence, particularly when the pollutant source is manure-treated pasture. This study assessed the effects of pollutant source area (fescue pasture treated with poultry litter) length and VFS (fescue pasture) length on VFS removal of nitrate N (NO3-N), ammonia N (NH3-N), total Kjeldahl N (TKN), ortho-P (PO4-P), total P (TP), …


Cultivar Selection, Seed Stratification And Surface Cover Effects On Switchgrass Establishment On Coal Mine Spoil, David C. Ditsch, Michael Collins, T. P. Demond, Timothy D. Phillips Jan 1996

Cultivar Selection, Seed Stratification And Surface Cover Effects On Switchgrass Establishment On Coal Mine Spoil, David C. Ditsch, Michael Collins, T. P. Demond, Timothy D. Phillips

Agronomy Notes

Surface mining in the Appalachian region of Kentucky often involves steep slopes and spoil limitations for revegetation not encountered in other reclamation situations. Herbaceous species (mono cultures or mixtures) provide quick cover required in revegetation of mined land for control of erosion as well as promoting soil development, improving wildlife habitat, and livestock production through hay and pasture production as well as a potential use as renewable energy for cofiring with high sulfur coal. However, due to the many challenging chemical and physical characteristics of mine spoil, selection of adaptable herbaceous species should be carefully considered.


1x27 Cartoons About Science, Mark S. Coyne Jan 1996

1x27 Cartoons About Science, Mark S. Coyne

Plant and Soil Sciences Faculty Book Gallery

A tongue-in-cheek look at the world of natural science.


Fish Lateral Line Neurophysiological And Neurobehavioral Responses As A Sensitive Water Quality Monitoring System, Hong Y. Yan Jan 1996

Fish Lateral Line Neurophysiological And Neurobehavioral Responses As A Sensitive Water Quality Monitoring System, Hong Y. Yan

KWRRI Research Reports

Cadmium is a heavy metal ion that can cause deleterious effects on aquatic animals. This study uses both electrophysiological recordings from lateral line nerves and videotaping of schooling behavior to investigate the effects of cadmium exposure on fish. The fathead minnows were exposed to cadmium at a concentration of 450 μg/1 over a 24-hr period. Extracellular recording with a silver hook electrode was used to record compound action potentials from the lateral lines of control and experimental fish. After a short time exposure (24 hr) to cadmium ions, all of the electrophysiological activities of the lateral line nerves were suppressed. …


Potential For Crop Residue To Restrict Herbicide Movement In Surface From Water Corn And Soybean Fields, William W. Witt Jan 1996

Potential For Crop Residue To Restrict Herbicide Movement In Surface From Water Corn And Soybean Fields, William W. Witt

KWRRI Research Reports

As no-tillage and other conservation tillage practices continue to increase, it is important to have knowledge of herbicide adsorption on crop residue with regard to the potential for the herbicide to be removed from the residue and move with runoff water from the field into nearby surface waters. Previous research had compared herbicide adsorption to various residues, but it was difficult to make comparisons among these studies because the residues were from different crops or the amount of residue decomposition was different. The amount of "weathering" or "aging" of the residue at the time of herbicide treatment could alter the …


So You Want To Be A Soil Microbiologist?, Mark S. Coyne Jan 1996

So You Want To Be A Soil Microbiologist?, Mark S. Coyne

Plant and Soil Sciences Faculty Book Gallery

A tongue-in-cheek look at soil microbiology.


Minimum Ventilation For Modern Broiler Facilities, Richard S. Gates, Douglas G. Overhults, Shuhui H. Zhang Jan 1996

Minimum Ventilation For Modern Broiler Facilities, Richard S. Gates, Douglas G. Overhults, Shuhui H. Zhang

Biosystems and Agricultural Engineering Faculty Publications

New functions for whole-house broiler heat production as a function of bird age using modern straight run broiler growth rates are presented and compared to values in the literature. The approximations are based on field measurements of environmental conditions in modern broiler housing, using a technique that matches predicted to actual fuel use to estimate partitioning between latent and sensible heat. Development of a program utilizing these approximations to compute ventilation and heating requirements for temperature and humidity control in broiler housing is described. The program utilizes steady-state heat and moisture balances commonly used for design purposes, with hourly or …


Vegetative Filter Strip Design For Grassed Areas Treated With Animal Manures, Dwayne R. Edwards, Tommy C. Daniel, Philip A. Moore Jr. Jan 1996

Vegetative Filter Strip Design For Grassed Areas Treated With Animal Manures, Dwayne R. Edwards, Tommy C. Daniel, Philip A. Moore Jr.

Biosystems and Agricultural Engineering Faculty Publications

Vegetative filter strips (VFS) are a low-cost management option that have been demonstrated to be effective in reducing runoff transport of fertilizer constituents applied to grassed areas (pasture or meadow). Runoff quality studies involving fertilizers applied to grassed areas suggest that VFS can be designed by assuming that (1) only infiltration is responsible for pollutant removal, (2) the first post-application runoff event is most important from a water quality perspective (enabling a design event approach), and (3) no pollutant build-up that degrades VFS performance will occur. The purpose of this study was to develop a VFS design algorithm for grassed …


A Direct, Approximate Solution To The Modified Green-Ampt Infiltration Equation, Puneet Srivastava, Thomas A. Costello, Dwayne R. Edwards Jan 1996

A Direct, Approximate Solution To The Modified Green-Ampt Infiltration Equation, Puneet Srivastava, Thomas A. Costello, Dwayne R. Edwards

Biosystems and Agricultural Engineering Faculty Publications

Accurately predicting the rainfall-runoff process is of vital importance for water quality models as well as for correct design of various types of hydraulic structures. This article presents a method of describing the cumulative infiltration process as an explicit function of time using an approximation to the modified Green-Ampt equation given by Mein and Larson (1971). The resulting equation is helpful in predicting cumulative infiltration and therefore infiltration capacity for computer simulation models. The proposed method takes about 50% less time than the usual iterative technique for the same degree of accuracy. The maximum error due to approximation was 1% …


Simulation Of Runoff Transport Of Animal Manure Constituents, Yang Wang, Dwayne R. Edwards, Tommy C. Daniel, H. Don Scott Jan 1996

Simulation Of Runoff Transport Of Animal Manure Constituents, Yang Wang, Dwayne R. Edwards, Tommy C. Daniel, H. Don Scott

Biosystems and Agricultural Engineering Faculty Publications

Runoff losses of land-applied animal manure constituents can adversely affect the quality of downstream waters. Reliable mathematical simulation models can help estimate runoff losses of animal manure constituents and identify management measures to reduce these losses. The objective of this study was to develop and calibrate an event-based simulation model to describe the runoff transport of solids (soil and manure particles) and nutrients (nitrogen and phosphorus) from areas treated with animal manure. The resulting model, consisting of linked hydrology, soil/manure transport, and nutrient transport components, is process-oriented and uses measurable parameters to the greatest degree possible. The three components of …


Quality Of Runoff From Four Northwest Arkansas Pasture Fields Treated With Organic And Inorganic Fertilizer, Dwayne R. Edwards, Tommy C. Daniel, John F. Murdoch, Philip A. Moore Jr. Jan 1996

Quality Of Runoff From Four Northwest Arkansas Pasture Fields Treated With Organic And Inorganic Fertilizer, Dwayne R. Edwards, Tommy C. Daniel, John F. Murdoch, Philip A. Moore Jr.

Biosystems and Agricultural Engineering Faculty Publications

Long-term land application of animal manures, even at agronomic rates, can promote accumulation of soil phosphorus (P) which can, in turn, contribute to increased P loadings to downstream waters. The objective of this study was to assess the soil and runoff effects of replacing animal manure as a soil amendment with inorganic fertilizer (ammonium nitrate, NH4NO3) on fields that had been treated previously with animal manures. Runoff from two pairs of small fields (0.57 to 1.46 ha) was sampled from September 1991 to April 1994. All fields had been treated previously with animal manures; after runoff …


Poultry Litter-Treated Length Effects On Quality Of Runoff From Fescue Plots, Dwayne R. Edwards, Philip A. Moore Jr., Tommy C. Daniel, Puneet Srivastava Jan 1996

Poultry Litter-Treated Length Effects On Quality Of Runoff From Fescue Plots, Dwayne R. Edwards, Philip A. Moore Jr., Tommy C. Daniel, Puneet Srivastava

Biosystems and Agricultural Engineering Faculty Publications

Using experimental data and/or mathematical simulation models to identify practices that reduce pollution from manure-treated areas is sometimes perceived as limited by the unknown validity of extrapolating plot-scale data to larger areas and by uncertainties in modeling transport of various pollutants. The objectives of this study were to assess the effect of length of manure treatment on runoff concentrations of poultry litter constituents and to define the modes of transport (particulate versus soluble) for nitrogen (N), phosphorus (P), carbon (C), and solids. Poultry litter was applied to three 1.5- x 18.3-m fescue (Festuca arundinacea Schreb.) plots with runoff collection …


Application Of Simplified Phosphorus Transport Models To Pasture Fields In Northwest Arkansas, Dwayne R. Edwards, C. T. Haan, Andrew N. Sharpley, John F. Murdoch, Tommy C. Daniel, Philip A. Moore Jr. Jan 1996

Application Of Simplified Phosphorus Transport Models To Pasture Fields In Northwest Arkansas, Dwayne R. Edwards, C. T. Haan, Andrew N. Sharpley, John F. Murdoch, Tommy C. Daniel, Philip A. Moore Jr.

Biosystems and Agricultural Engineering Faculty Publications

Runoff transport of phosphorus (P) is often predicted from simple equations with parameters determined from data applicable primarily to row-cropped and fallow cover conditions. The applicability, accuracy, and precision of such P transport prediction equations under pasture situations are less well defined. The objectives of this study were to determine parameters of simplified runoff P transport equations for pasture fields and to assess the accuracy and precision of the equations. Runoff, sediment yield, soluble P transport, and particulate P transport data were collected from four pasture fields in northwestern Arkansas. Runoff event enrichment ratios and extraction coefficients were computed, and …


Development Of A Biologically Based Aerobic Composting Simulation Model, Dennis P. Stombaugh, Sue E. Nokes Jan 1996

Development Of A Biologically Based Aerobic Composting Simulation Model, Dennis P. Stombaugh, Sue E. Nokes

Biosystems and Agricultural Engineering Faculty Publications

A relatively simple dynamic model based on microbial process kinetics has been developed for aerobic composting. Differential equations describing microbial, substrate, and oxygen concentrations, as well as moisture and temperature profiles have been derived as a function of vessel size and aeration rate. Microbial biomass growth was described using Monod growth kinetics as a function of degradable substrate concentration, oxygen concentration, moisture content, and compost temperature. Facility and fan operating costs have been included to permit economic optimization of the process. Predicted results demonstrated the ability of the model to quantify and describe the influence of multiple interacting factors (temperature, …


Nitrous Oxide Loss From Poultry Manure-Amended Soil After Rain, Mark S. Coyne, A. Villalba, Robert L. Blevins Nov 1995

Nitrous Oxide Loss From Poultry Manure-Amended Soil After Rain, Mark S. Coyne, A. Villalba, Robert L. Blevins

Plant and Soil Sciences Faculty Publications

Land application of poultry wastes in Kentucky will increase as the broiler industry grows. If poultry manure stimulates N2O loss from soil it will reduce the fertilizer N value of this waste. In contrast, stimulated N2O loss in grass filter strips receiving the runoff from manured fields could help reduce contamination of surface water by NO−3. Our objectives were to determine (i) if poultry manure stimulated N2O loss in soil after rainfall and (ii) if there was an edge-of-field effect on N2O loss in grass filters intercepting runoff from …


Involvement Of P59FynT In Interleukin-5 Receptor Signaling, Mark W. Appleby, James D. Kerner, Sylvia Chien, Charles R. Maliszewski, Subbarao Bondada, Roger M. Perlmutter Sep 1995

Involvement Of P59FynT In Interleukin-5 Receptor Signaling, Mark W. Appleby, James D. Kerner, Sylvia Chien, Charles R. Maliszewski, Subbarao Bondada, Roger M. Perlmutter

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Previous studies implicate the nonreceptor protein tyrosine kinase (PTK) p59fyn in the propagation of signals from the B cell antigen receptor. To elucidate the functions of this kinase, we examined B cell responsiveness in mice engineered to lack the hematopoietic isoform of p59fyn. Remarkably, antigen receptor signaling was only modestly defective in fynTnull B cells. In contrast, signaling from the interleukin (IL)-5 receptor which ordinarily provides a comitogenic stimulus with antiimmunoglobulin, was completely blocked. Our results document the importance of p59fynT in IL-5 responses in B cells, and they support a general model …


Fecal Bacteria In Agricultural Waters Of The Bluegrass Region Of Kentucky, J. M. Howell, Mark S. Coyne, P. L. Cornelius May 1995

Fecal Bacteria In Agricultural Waters Of The Bluegrass Region Of Kentucky, J. M. Howell, Mark S. Coyne, P. L. Cornelius

Plant and Soil Sciences Faculty Publications

Agricultural runoff influenced by nonpoint pollution frequently exceeds the USEPA standards for bacterial contamination of primary contact water (200 fecal coliforms/100 mL). Few studies have evaluated the effect of cattle (Bos taurus) grazing on fecal contamination of ground water in the karst topography of central Kentucky. Our objectives were to: (i) observe the extent and pattern of fecal bacteria in agricultural waters from two central Kentucky watersheds; (ii) determine if monthly sampling accurately assessed the extent and variability of fecal contamination; and (iii) assess the fecal coliform/fecal streptococci ratio (FC/FS) as an indicator of fecal bacteria source. Springs, …


Condition Scoring For Your Horse, Craig H. Wood Apr 1995

Condition Scoring For Your Horse, Craig H. Wood

Agriculture and Natural Resources Publications

In a world where millions of people are taking steps to improve their own physical condition in order to live healthier lives, it only stands to reason that this same concept would be applied to other aspects of their lives and businesses. In Kentucky where horses are a multi-billion dollar industry, the health and welfare (condition) of the horses are of utmost importance to their owners. The ability to accurately assess a horse’s body condition, which is vital to its welfare, weighs heavily on the industry.


What Leading Alfalfa Growers Do To Produce Quality Hay, Jimmy C. Henning, Garry D. Lacefield, Buddy Sims Feb 1995

What Leading Alfalfa Growers Do To Produce Quality Hay, Jimmy C. Henning, Garry D. Lacefield, Buddy Sims

Kentucky Alfalfa and Stored Forage Conference

Alfalfa is the highest quality forage legume crop grown in Kentucky and is the number one cash hay crop. Hay raised by Kentucky farmers has been recognized for its quality at local, state (state fair and Kentucky Alfalfa Conference), and national (American Forage and Grassland Council) hay contests. The testing records of the Kentucky Department of Agriculture also document the high quality alfalfa hay of Kentucky. However, little has been written about the farm practices used to produce high quality alfalfa hay in Kentucky. The current practices of top hay growers may be helpful in defining the options available to …


How To Make Your Alfalfa More Profitable, Clive Holland Feb 1995

How To Make Your Alfalfa More Profitable, Clive Holland

Kentucky Alfalfa and Stored Forage Conference

As a perennial plant, alfalfa can be expected to continue to live and produce for an indefinite period of time. Why then do stands need to be replanted every few years? Is modern seed available today, weakened and unable to live up to the perennial label? What about yield? How does your stand measure up? Are you barely making the state average, or struggling to even meet this modest yield level?

The first harvest each spring can produce over 40% of the yield in a single growing season. Why is a stand slower growing in the spring than you would …


Role Of Alfalfa In Animal Diets, Jennifer L. Garrett Feb 1995

Role Of Alfalfa In Animal Diets, Jennifer L. Garrett

Kentucky Alfalfa and Stored Forage Conference

Alfalfa forage use has increased in all classes of livestock - dairy, beef, horses, sheep, and swine - during the last 40 years. The highest utilization of alfalfa by livestock is found in dairy cattle diets. Additionally, the use of alfalfa as a grazing crop has also undergone a considerable increase with the use of new grazing management techniques and the development of new grazing varieties.

Alfalfa's strength as a forage crop is its high nutritional value. Alfalfa is higher in protein, minerals, and net energy than grasses and small grains. High quality alfalfa also helps to promote intake, especially …


Saving Those Valuable Leaves During Haymaking, Michael Collins Feb 1995

Saving Those Valuable Leaves During Haymaking, Michael Collins

Kentucky Alfalfa and Stored Forage Conference

Field dry hay needs to be reduced from near 80% moisture to 20% or less to prevent spoilage during storage. Drying hay to safe baling moistures often takes several days. Sources of loss during forage harvest include mechanical losses such as mowing, conditioning, chopping, raking, packaging and handling as well as respiration and leaching. The general relationship between forage moisture concentration at harvest and losses during the field and storage phases is shown in Figure 1. Harvest losses are greatest for very dry forage and are low for very wet material like direct cut silage. However, the latter is subject …


Alfalfa As A Grazing Crop: Progress Continues, Garry D. Lacefield Feb 1995

Alfalfa As A Grazing Crop: Progress Continues, Garry D. Lacefield

Kentucky Alfalfa and Stored Forage Conference

This makes the third consecutive year that I have talked about "Alfalfa as a Grazing Crop". At our XIII Kentucky Alfalfa, I, along with five other speakers, discussed several aspects of grazing alfalfa and all agreed that the concept had tremendous potential.

This past year I reviewed some of the discussion of our XIII Conference and shared some of the activities going on in research and educational programs throughout the region. In addition, I announced the date for a National Alfalfa Grazing Conference to be held in Nashville, Tennessee. The Conference was held July 29 and was a big success. …