Physical Sciences and Mathematics Commons^™

Mathematical Programming Applications In Agroforestry Planning, Laurence H. Reeves

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Agroforestry as a sustainable production system has been recognized as a land use system with the potential to slow encroachment of agriculture onto forested lands in developing countries. However, the acceptance of nontraditional agroforestry systems has been hampered in some areas due to the risk-averse nature of rural agriculturalists. By explicitly recognizing risk in agroforestry planning, a wider acceptance of agroforestry is possible. This thesis consists of a collection of three papers that explore the potential of modern stock portfolio theory to reduce financial risk in agroforestry planning.

The first paper presents a theoretical framework that incorporates modern stock portfolio …

The Effect Of Design And Dose Level Choice On Estimatlng The Optimal Dose In A Quantitative Dose-Response Experiment, Henry R. Rolka, George A. Milliken, James R. Schwenke, Marta Remmenga

Conference on Applied Statistics in Agriculture

D-optimality is a commonly used criterion to evaluate a design with respect to parameter estimation. The variance of the optimal dose estimate is another criterion for evaluating a design. The quantitative dose-response experiment involves fitting a model to data and estimating an optimal dose. Two techniques for estimating an optimal dose and three models are used to compare the variances of optimal dose estimates over nine equally spaced balanced designs and five fixed unequally spaced six-point designs. The results show that a design which is more D-optimal than another design does not necessarily produce optimal dose estimates with less variance.

Analysis Of Genotype X Environment Interaction By Graphical Techniques, George C.J. Fernandez

Conference on Applied Statistics in Agriculture

Genotype x Environment interactions results from the changes in the magnitude of differences among genotypes (non-crossover or quantitative interactions) or changes in the relative ranking of the genotypes (crossover or qualitative interactions) in different environments. Non-crossover interactions are usually associated with variance heterogeneity and non-additivity. The analysis of variance combined with joint regression analysis failed to differentiate between the crossover and non-crossover interactions. Tedious computations are necessary in comparisons of all possible pairs of genotypes in all possible pairs of environments in the crossover detection tests. Therefore, differentiating the non-crossover interaction caused by variance heterogeneity and non-additivity from crossover interaction …

Analysis Of The Spatial Distribution Of Sugarbeet Plants, Stephen D. Kachman, John A. Smith

Conference on Applied Statistics in Agriculture

The spatial distribution of emerged sugarbeet plants is an important aspect of the performance of sugarbeet planters. Three major components influencing the spatial distribution are the ability to drop a single seed at a time, the ability to drop the seeds a fixed distance apart, and the ability of the seed to emerge. A model has been developed to describe the distribution of the spacing between emerged sugarbeet plants. The model consists of a mixture of normal and gamma distributions. The spatial data consists of the distance between neighboring emerged plants. Spatial data was collected on 7 planters operated at …

Evaluation Of Four Covariate Types Used For Adjustment Of Spatial Variability, Paul N. Hinz, John P. Lagus

Conference on Applied Statistics in Agriculture

Four types of covariates are used to account for spatial variability in data from a field experiment for evaluating 620 soybean varieties for iron chlorosis. The covariates are calculated as the average of 4 and of 14 neighboring residuals and of 4 and of 14 neighboring observations. The residual mean square from the analysis of covariance was smaller' when residuals were used in calculation of the covariates than when observations were used. Moreover, use of 14 neighbors resulted in smaller residual mean squares than did use of 4 neighbors. Differences among 4 covariate types were small and not practically important. …

Multi-Product Dry Milling Yields Prediction When Products Are Not Independent, Aziz Bouzaher, Alicia L. Carriquiry

Conference on Applied Statistics in Agriculture

The yield of products in the dry milling industry is largely determined by the physical properties of the corn kernel. The main objective of this paper is to investigate several statistical models of dry milling yield prediction based on physical characteristics of corn. Data consisting of one hundred corn samples representing a range of genetic traits and quality differences are used. For each corn sample, sixteen physical and chemical properties together with six dry milling product yields were measured, in a controlled laboratory environment .

For each corn sample, we consider a vector of dry milling product yields, and a …

Messy Experimental Designs, Dallas E. Johnson

Conference on Applied Statistics in Agriculture

This paper describes the statistical analysis of an agricultural experiment that was conducted in a very complex, but somewhat reasonable, experimental design. A correct analysis of data collected from the experimental design used requires the estimation of 8 error terms.

A Statistical Analysis Of The Performance Of Milking System Vacuum Regulators, Linda J. Young, Gerald R. Bodman, Eugene C. Boilesen, Walter W. Stroup

Conference on Applied Statistics in Agriculture

Milking machine vacuum regulators were tested at dairies across the United States over a period of twelve years. The drop in vacuum level with increasing air flow for each regulator tested was modeled using segmented regression. Three measures of regulator performance were considered: the slope of the line in the first phase, the variability about the first line, and the join point (after which vacuum pressure began to drop rapidly). The distribution of the join point was estimated based on an accelerated failure time model with censoring, Weibull errors, a model effect, and a linear effect of set point vacuum. …

Evaluation Of Methane Gas Production In A Simultaneous Regression System, Mark W. Jenner, Jon Maatta, Dennis M. Sievers

Conference on Applied Statistics in Agriculture

Methane gas production is a function of volatile solids activity in anaerobic digesters. Increasing the solids retention time of the swine manure digester system without increasing the hydraulic retention time would theoretically increase the methane gas production efficiency. Coagulation treatments were performed on the effluent of the second digester in a system of two digesters in series .

The objective of this paper is to describe mathematically the relationship of the Coagulation treatments in the second digester to biogas production and volatile solids retention. An initial, single equation, ordinary least squares regression produced statistically significant parameter estimates, but failed to …

A Reevaluation Of The Growth Decline In Pine In Georgia, And In Georgia-Alabama Combined, Z. Ouyang, H. T. Schreuder, J. Li

Conference on Applied Statistics in Agriculture

Using an improved testing procedure based on bootstrap and weighted jack-knife confidence intervals with the same model as used in Bechtold et al. (1991) and Ruark et al. (1991), analysis in this paper generally confirm the results of a significant decrease in growth rate in pine in Georgia and Alabama for 1972 - 1982 (5th cycle) relative to 1961 - 1972 (4th cycle) discussed in these papers.

Shrinkage In Ternary Mixes Of Container Media, Silvia Bures, Franklin A. Pokorny, Glenn O. Ware

Conference on Applied Statistics in Agriculture

Based on functional relationships established for binary mixes of container media, a mathematical model is proposed for ternary component mixtures. Shrinkage values are generated for three-component mixtures based on mathematical equations. Empirically observed shrinkage values for corresponding three-component mixtures are determined and used as the basis for assessing the reliability of the proposed mathematical model for characterizing shrinkage in mixtures of container media. . Regression equations were developed and compared for both theoretical and empirical results.

Nonlinear Estimation Of Growth Curve Models For Germination Data Analysis, Bahman Shafii, William J. Price, Jerry B. Swensen, Glen A. Murray

Conference on Applied Statistics in Agriculture

Logistic, Gompertz, Richards and Weibull growth curves were evaluated for their suitability as mathematical and empirical models to represent cumulative germination. By avoiding the limitations associated with the method of moments and single-value germination indices, the fitted models provided superior description of the time course of germination. The four-parameter Weibull model gave the best fit across a relatively wide range of seed species and germination conditions, and the resulting parameter estimates reflected identifiable aspects of the germination process. The nonlinear estimation of the germination response included a parameter summary, together with their asymptotic standard errors and correlation matrix, along with …

Straight Line Regression When Both Variables Are Subject To Error, Norman R. Draper

Conference on Applied Statistics in Agriculture

This expository note discusses the problem of fitting a straight line when both variables are subject to error. A brief review of the literature is undertaken, and one fitting method, the geometric mean functional relationship, is spotlighted and illustrated with two sets of example data. The emphasis is on providing practical advice. All methods have drawbacks, but the geometric mean functional relationship method appears to provide a sensible course of action in many practical problems, and could benefit from further investigation.

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

Conference on Applied Statistics in Agriculture

These proceedings contain papers presented at the third annual Kansas State University Conference on Applied Statistics in Agriculture, held in Manhattan, Kansas, April 28 through 30, 1991.

Background Papers To Wawa's South-West Irrigation District Strategy Study, G J. Luke, I Af Laing, P R. George, G R. Olney, R L. Taylor, I F. Wilkinson, P T. Arkell

Resource management technical reports

No abstract provided.

Pasture Condition Guides For The Murchison River Catchment, A Fox, T R. Eckersley

Soil conservation survey collection

Knowledge of the pasture resource and its capabilities is essential to sustainable use of the rangelands. Rangeland managers must be able to recognise firstly the different pasture types, and secondly, the differences between present condition classes for each type. Both factors affect the stock carrying capacity, and appropriate pastoral management of a pasture. This guide has been produced for use by pastoralists to assist them to recognise and assess the condition of the perennial pasture resource of their own properties. The guide describes the condition states found in 10 of the most widespread pastures of the Murchison River catchment (Fig. …

Deep Tillage : Keep An Eye On Costs As Well As Yields, Amir Abadi, Andrew Bathgate

Journal of the Department of Agriculture, Western Australia, Series 4

Deep tillage overcomes compaction of sandy soils caused by movement of heavy machinery. Many experiments since 1981 have shown cereal yields improve as a result of deep tillage. However, the increased yield does not necessarily mean more profit when costs are taken into account. To determine the profitability of deep tillage farmers must consider its impact on other farm operations. A whole-farm analysis is needed to accurately determine the increase in profit resulting from deep tillage

Land Capability Study For Horticulture In The Swan Valley, J M. Campbell-Clause, Geoff Allan Moore

Land resources series

The Swan Valley is an important agricultural, recreational, tourist and heritage area in which there are a number of competing land uses because of its location close to Perth. The traditional agricultural use, mainly centred around the viticulture industry, has to compete with tourist development, urban encroachment, hobby farms and clay extraction. The major objective of this report was to identify any areas of prime horticultural land which should be retained for that purpose. A land capability study was done using the existing soil series map of the Swan Valley (Pym 1955), which covers most of the Swan Valley Policy …

Manual Of Field Techniques In Hydrology, Department Of Agriculture, Western Australia. Division Of Resource Management

Agriculture reports

No abstract provided.

An Introduction To The Soils Of The Katanning Advisory District, T C. Stoneman, National Soil Conservation Program (Australia)

Bulletins 4000 -

With descriptions, illustrations and notes on eight common soils.

An Introduction To The Soils Of The Narrogin Advisory District, T C. Stoneman, Department Of Agriculture And Food, National Soil Conservation Program (Australia)

Bulletins 4000 -

Descriptions, illustrations and notes on eight common soils / compiled by T.C. Stoneman.