Physical Sciences and Mathematics Commons^™

Wavelet Nonparametric Regression With Dependent Data, Chengjie Xiong, George A. Milliken

Conference on Applied Statistics in Agriculture

Estimation of the regression function has many applications in agriculture and industry. Usually, the regression function is assumed a known functional form which depends on unknown parameters. Nonparametric regression theory makes no such assumption and often uses some kernel functions to form the so-called Watson Nadaraya type estimators. Such estimators were extensively studied by Watson (1964), Nadaraya (1964, 1989) and Collomb (1981, 1985). When the data are independent, these estimators have nice asymptotic convergence properties. When the data are dependent, Gyorfi et al (1989) gave some large sample properties for the Watson-Nadaraya estimators. In this paper, the recently developed theory …

Validity Of 95% T-Confidence Intervals Under Some Transect Sampling Strategies, Stephen N. Sly, Jeffrey S. Pontius, James J. Higgins

Conference on Applied Statistics in Agriculture

Soil pH data were used to assess the capture rates of 95 % t-confidence intervals based on five different transect sampling strategies. Two different sampling methods were considered, "deterministic" and "two-stage simple random sampling". The data used were pH readings at 15 and 30 centimeter depths from two local agricultural fields in the Manhattan, Kansas area. The data provided three distinct populations with three different distributions - skewed left, symmetric, and bimodal. The total number of transects randomly sampled was 2, 5, and 10. The total number of points sampled along each transect was 2, 7 and 14. The 95% …

Designing Speech Interface Applications For Acquisition Of Agricultural Information, Jeffrey Willers, Susan Bridges, Xiaofeng Ma, James Mckinion, Jean Liang

Conference on Applied Statistics in Agriculture

It will be argued that customary software design strategies, by themselves, fall short when designing speech recognition applications. Concepts of experimental design and analysis are also necessary for developing speech interface software. This study demonstrates that these tools can be advantageous to the software developer, especially if the prototype methodology model of software development is applied. A case study for the problem of developing a speech interface for collecting, or mapping, information on cotton plant growth is presented. The acquisition of cotton plant map data is a 'hands and eyes' busy task that requires considerable investment to record and convert …

A New Approach To Teaching Natural Resource Sampling, Kenneth M. Portier, Loukas G. Arvanitis, Daniel Brackett

Conference on Applied Statistics in Agriculture

A basic undergraduate course in statistics is often not adequate for students in renewable natural resource programs such as wildlife, forestry, fisheries, and related subjects. A strong foundation in the basics of sampling in time and space of forest, vegetation, wildlife and fish populations is needed. A brief account of our experience in teaching such a course over the last three years along with progress on developing course-related material and activities is reported. This includes the development of: 1) computer-based simulations; 2) in-class participation simulations to illustrate the basic concepts of sampling in space and time; 3) exercises to introduce …

Experimentation Science: A Process Approach For The Complete Design Of An Experiment, D. D. Kratzer, K. A. Ash

Conference on Applied Statistics in Agriculture

Experimentation Science is introduced as a process through which the necessary steps of experimental design are all sufficiently addressed. Experimentation Science is defined as a nearly linear process of objective formulation, selection of experimentation unit and decision variable(s), deciding treatment, design and error structure, defining the randomization, statistical analyses and decision procedures, outlining quality control procedures for data collection, and finally analysis, presentation and interpretation of results. The protocol description form (PDF) is introduced as an instrument to guide the implementation and documentation of the Experimentation Science process.

Markov Chain Monte Carlo Methods For Modeling The Spatial Pattern Of Disease Spread In Bell Pepper, Jonathan M. Graham

Conference on Applied Statistics in Agriculture

With exponential family models for dependent data, such as the autologistic model for binary spatial lattice data, maximum likelihood estimates can be obtained using Markov chain sampling methods by simulating an ergodic Markov chain which converges weakly to the equilibrium distribution of the model. This Markov chain Monte Carlo maximum likelihood (MCMCML) procedure provides a competitor to the usual pseudolikelihood estimation method often used for modeling discrete lattice data. Within this MCMCML framework, it is also possible to conduct formal inference using MCMC analogues to the usual likelihood ratio, Wald, and Lagrange multiplier tests, for which the asymptotic distributions are …

Confidence Intervals For The Coefficient Of Variation, Mark E. Payton

Conference on Applied Statistics in Agriculture

The coefficient of variation (CV), defined as the ratio of the standard deviation to the mean, is often used in experimental situations. The exact distribution of the sample CV from a normally distributed population is complicated and obtaining a confidence interval for the population CV in this situation would require using the non-central t distribution and sequential techniques (Koopmans, et al., 1964). This paper explores the use of approximate distributions in determining confidence limits for the CV. The gamma distribution is used to model data appropriate for the calculation of the CV. A Monte Carlo simulation is performed to evaluate …

Estimation Of Kinetic Parameters Associated With Nutrient Uptake By An Intact Plant Root System, Edward Gbur, Craig Beyrouty

Conference on Applied Statistics in Agriculture

Several mechanistic models have been developed for the prediction of nutrient uptake at low concentrations from the soil by a plant root system. Claassen and Barber (1974 Plant Physiology 54, 564-568; 1976 Agronomy Journal 68, 961-964) presented an experimental procedure to obtain data from intact plants to fit an ion depletion curve and used the data in a model which they developed to predict nutrient uptake. Their model assumed that nutrient absorption from the soil solution followed Michaelis-Menten kinetics. In this paper, we develop a stochastic version of the Claassen-Barber model and illustrate its application to the estimation of the …

Analysis Of Unbalanced Mixed Model Data: Traditional Anova Versus Contemporary Methods, Ramon C. Littell

Conference on Applied Statistics in Agriculture

Analysis of unbalanced data and analysis of mixed model data are important topics of statistical discussion. Analysis of unbalanced data with fixed effects gives rise to the different types of sums of squares in analysis of variance. Mixed model riata raises issues of determining appropriate error terms for test statistics and standard errors Clf estimates. The situation is even more difficult when the two topics occur together, resulting in unbalanced mixed model data. These problems have plagued users ofPROC GLM in the SAS System. Now, with PROC MIXED available, some of the problems are resolved while others remain. This paper …

Analysis Of Proportions From Split-Plot And Repeated Measures Experiments, Kenneth J. Koehler

Conference on Applied Statistics in Agriculture

Several methods for analyzing proportions from split-plot and repeated measures experiments are illustrated and compared. One approach simply uses analysis of variance for the usual linear mixed model fit to split-plot and repeated measures experiments. Alternatively, logistic regression analysis is considered and a so-called robust estimate of the covariance matrix is used to adjust for possible correlations among responses. Finally, a quasi-likelihood approach to logistic regression analysis that requires more explicit specification of the covariance structure for the observed proportions is considered. These methods are illustrated with the analyses of data from a repeated measures study of acorn consumption by …

Estimation Of Cardinal Temperatures In Germination Data Analysis, Cindy Roche, Bahman Shafii, Donald C. Thill, William J. Price

Conference on Applied Statistics in Agriculture

Seed germination is a complex biological process which is influenced by various environmental and genetic factors. The effects of temperature on plant development are the basis for models used to predict the timing of germination. Estimation of the cardinal temperatures, including base, optimum, and maximum, is essential because rate of development increases between base and optimum, decreases between optimum and maximum, and ceases above the maximum and below the base temperature. Nonlinear growth curves can be specified to model the time course of germination at various temperatures. Quantiles of such models are regressed on temperature to estimate cardinal quantities. Bootstrap …

Long-Term Tillage Effects On Continuous Corn Yields, T. B. Bailey, J. B. Swan, R L. Higgs, W. H. Paulson

Conference on Applied Statistics in Agriculture

Long-term comparisons of alternative tillage systems are needed to evaluate their effect on corn (Zea mays L.) yield under the variable temperature and rainfall conditions of the Corn Belt. Our objective was to evaluate long-term effects of alternative tillage systems on corn growth and yield on low organic matter silt loam soils. The effect of no-tillage (NT), chisel plow (CP), and moldboard plow (MP) treatments on plant density and grain yield was measured from 1981 through 1990 on Palsgrove and Rozetta silt loam (fine-silty, mixed mesic Typic Hapludalfs) soils. Tillage treatments were randomly allocated to plots in 1981 …

An Introduction To Generalized Linear Mixed Models, Charles E. Mcculloch

Conference on Applied Statistics in Agriculture

The generalized linear mixed model (GLMM) generalizes the standard linear model in three ways: accommodation of non-normally distributed responses, specification of a possibly non-linear link between the mean of the response and the predictors, and allowance for some forms of correlation in the data. As such, GLMMs have broad utility and are of great practical importance. Two special cases of the GLMM are the linear mixed model (LMM) and the generalized linear model (GLM). Despite the utility of such models, their use has been limited due to the lack of reliable, well-tested estimation and testing methods. I first describe and …

Editor's Preface, Table Of Contents, And List Of Attendees, George A. Milliken

Conference on Applied Statistics in Agriculture

These proceedings contain papers presented in the eighth annual Kansas State University Conference on Applied Statistics in Agriculture, held in Manhattan, Kansas, April 28-30, 1996..

Marketing Options For Quality Kentucky Alfalfa Hay, Tom Keene

Kentucky Alfalfa and Stored Forage Conference

As today's farmer becomes more and more business like, running his farming operation as a commercial business, the production of alfalfa hay should be treated no differently. When the farmer makes the decision to plant alfalfa, he should have already done a great deal of research and given a great deal of thought into the markets he is going to try to target for his product. Any successful commercial business looks into market potential even before production begins, whether they produce toys, cars, appliances, computers, etc. Alfalfa hay production should be no different in regards to seeking out various markets …

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 …

Are We Making Progress With Hay Quality In Kentucky?, Buddy Sims

Kentucky Alfalfa and Stored Forage Conference

During the Kentucky State Fair, Garry Lacefield asked if I would be on the XVI Kentucky Alfalfa Conference program. Certainly I never miss an opportunity to talk, especially about testing forages. Then in October we communicated again and it was decided that my topic would be "Are We Making Progress With Hay Quality in Kentucky?" Seems like a simple yes or no question! Well ... l elected to think about this under the middle of December. Of course, during this time, the people of the Commonwealth elected a new Commissioner of Agriculture. Your selection was Billy Ray Smith, who throughout …

Role Of Alfalfa In Our Farming Operation, Larry Jeffries

Kentucky Alfalfa and Stored Forage Conference

Our farming operation consists of 214 acres. We raise 14,000 pounds of tobacco, have a purebred beef cattle herd, and sell hay. Alfalfa is the only one of the three sources of income that we can project an increase for 1996.

Our alfalfa cash hay sales have increased for several years due to the increase of suburban horse owners in the Louisville area.

I think it is important to have a written plan for 1996. We wouldn't think of making a long trip without a map, especially into strange territory - we farmers are in strange territory. If you don't …

Utilizing Alfalfa Hay In Horse Diets, Laurie Lawrence

Kentucky Alfalfa and Stored Forage Conference

All horses need fiber in their diets. Forages, usually as pasture or hay, are the primary sources of fiber in most rations. The exact amount of hay that a horse will eat on a daily or yearly basis will depend on the size of the horse, the class of the horse (pregnant, working, etc) and the type of hay being fed. The type and amount of other feeds in the ration will also impact the amount of hay consumed, but in general, horse owners/managers should try to maximize forage intake and then supplement with grain or other feeds to meet …

Advances In Harvesting And Storing High Quality Alfalfa, Michael Collins

Kentucky Alfalfa and Stored Forage Conference

On suitable soils, alfalfa produces the highest yields of dry matter and nutrients possible under Kentucky conditions. Limitations to achievement of this potential are often related to losses that occur during alfalfa harvest and storage. We have conducted a number of studies addressing technologies designed to minimize the extent of these losses.

Fencing And Watering Systems For Grazing Alfalfa, Larry Turner

Kentucky Alfalfa and Stored Forage Conference

Controlled or rotational grazing can result in better utilization of the forage resources on your farm. By better forage management through controlled grazing, you can increase profitability of cattle/forage systems. To effectively develop a controlled grazing system, however, fencing must be used to subdivide the pasture into sub-fields or paddocks. The animals may then be rotated among the paddocks to optimize forage and beef or dairy production from the system. Alfalfa grazing can play an important part in such a system. By using alfalfa, additional grazing management options are available, including avoiding high-endophyte fescue in hot summer periods thereby gaining …

Opportunities For Alfalfa As A Grazing Crop In Kentucky, Ken Johnson

Kentucky Alfalfa and Stored Forage Conference

As we think about the possibilities of alfalfa as a grazing crop, maybe we need to look at some of the limitations and where alfalfa may fit into Kentucky producers programs.

When looking at Kentucky's land area of 25 million acres we see that nearly half is in woodland. Of the 12 million acres remaining; about 3 million is in row crops, 2 million in hay, 2 million in non farm uses, and the rest is pasture. That is about 5 million acres in pasture or at least available to the pastured. With at least 7 million acres in hay …

Grazing Alfalfa: Putting The Puzzle Together, Garry D. Lacefield, Jimmy C. Henning, David Stalion

Kentucky Alfalfa and Stored Forage Conference

Interest in alfalfa as a grazing crop has increased dramatically over the past decade. There are many research and demonstrations being conducted in Kentucky and across the U.S. as we continue to investigate and learn more about alfalfa's role in forage-based livestock production.

Listed below are some of the reasons farmers, researchers and agribusiness personnel are excited about the opportunity for alfalfa as a grazing crop.

Foreword [1996], Garry D. Lacefield, Christi L. Forsythe

Kentucky Alfalfa and Stored Forage Conference

This is the front matter of the proceedings.