Document Type

Dissertation - University Access Only

Award Date

2003

Degree Name

Doctor of Philosophy (PhD)

Department / School

Plant Science

First Advisor

Gregg Carlson

Abstract

Seven county Extension educators volunteered and participated in an on-farm, site-specific research study. The study was designed to evaluate the effectiveness of participatory research as a training method for Extension educators, determine the sitespecific response of yield to levels of phosphorus, and develop and evaluate methods to prepare and analyze strip trial data. Educators were asked to participate in all facets of conducting the research and retrieving yield monitor. In addition they were provided with an intense one credit graduate course involving agronomic aspects of site-specific agriculture. A survey of educators at the conclusion of the study found that as a result of participation in this study (based on a 1 to 5 Likert scale) most recommended this method of training (4.0), most would be more likely to discuss (3.8), present (3.3), or conduct (3.7) site-specific on-farm research with producers. A high ranking (4.6) suggested that they strongly supported this method as a training for Extension educators. Four locations across eastern and central South Dakota were selected based on expected low (Olsen) phosphorus test levels and varied topography. Plot areas were soil sampled on a ½ acre grid and formatted to be consistent with normal fanning practices. Strips of three levels of phosphorus (0, 100, and 200 pound per acre) were bordered with a 50 pound per acre treatment. Weather and physical constraints confounded treatment effects. The Brown County location in 2000 was the only location showing a significant treatment effect (P > .10) when analyzed as strip treatment means. Regression of data showed yield positive response to added phosphorus in nine of twelve phosphorus level by location years. Tools to parse and evaluate site-specific treatment data were developed. Visual Basic™ code written as macros with in Excel™ to clean, delineate treatments and sum means of site-specific strip treatment data. Semi-variograms were used in an experimental attempt to identify data independence and parse replications within strips in an attempt to increase the ability to detect treatment differences from on-farm research. Although results were variable, this method deserves further study.

Library of Congress Subject Headings

Agricultural extension workers -- Training of -- South Dakota.
Agriculture -- Research -- South Dakota -- On-farm.
Participant observation.
Precision farming.
Phosphorus in agriculture.

Publisher

South Dakota State University

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Rights Statement

In Copyright