Agdex (6/18/2021)

Agdex is (was)

  1. A filing system used by agriculture teachers and extension agents.
  2. A national directory of agricultural teachers and extension agents.
  3. A listing of agricultural companies that provide(d) free teaching aids to teachers and agents.
  4. A specialized futures market where agricultural commodities were/are bought and sold.

If you selected A, you are correct. Officially Agdex is described as “A System for Classifying, Indexing, and Filing Agricultural Publications.” It was created in 1959 at The Ohio State University.

This Footnote is a continuation of the theme of things that once were in agricultural and extension education but have faded away over time. Now, let’s learn about Agdex.

The Problem

Filing teaching materials and agricultural bulletins has historically been a challenge for agriculture teachers and extension agents. Some teachers and agents have piles and piles of materials stacked up on their desks, on top of filing cabinets, and any other place capable of stacking materials. If the teacher or agent has to find something, it is challenging.

This problem is illustrated by a humorous story titled “Joe Loses Bulletins”. The story was written in the 1950s by E. V. Walton at Texas A&M about a fictitious ag teacher – Joe Scatterscrew. As a special bonus to this Footnote, that story can be accessed via this link. Enjoy.

A perusal of The Agricultural Education Magazine over time reveals that filing of teaching material has been a concern of agriculture teachers. Iverson and Jacks wrote about this problem (1976, p.56):

A rising flood of paperwork, instructional supplies and related materials threatens to inundate vocational agriculture departments and teachers of agriculture throughout the nation. Unless proper steps are taken to manage this “flood,” the effectiveness of beginning and experienced teachers alike may suffer.

Iverson and Jacks identify some of the potential problems associated with the “flood” – eyesores to visitors, delayed reports, lost materials, confusion, and the list goes on. The authors then go on to make recommendations on what to do to solve the problem.

Iverson and Jacks also wrote (1976, p. 56):

Clearly, every Vo-Ag department needs a systematic means to handle, file and store departmental materials. Busy teachers of agriculture can find few better uses for their time than those hours spent organizing their office facilities, storage and filing systems for efficient operation. Setting aside a few days for organization at the beginning of the school year will pay dividends that year and for years to come.

If a teacher or agent developed a good filing system and then moved to a new county or state, the previous teacher or agent might have had an entirely different filing system or no system at all. Wouldn’t it be wonderful if there was a uniform filing system all agriculture teachers and extension agents across the country used? In 1955 the National Vocational Agricultural Teachers Association had recommended exploring the possibility of a national indexing or filing system for agricultural publications.

The voices were heard and an uniform system for filing agricultural materials was developed. It was known as Agdex. In the Iverson & Jacks article they write (1976, p. 57):

Agdex is undoubtedly the most comprehensive standardized system available for vocational agriculture departments; as such it probably should be used in all departments. In addition to being standardized and comprehensive, Agdex saves time by providing pre-coded stickers for marking divisions. The teacher has only to study the system and then put it into use.

How Did Agdex Get Started?

When I advise doctoral and master’s students about selecting a thesis/dissertation topic I encourage them to pick a topic of importance and significance to the profession. After all, the same amount of work is involved in researching a Micky Mouse topic as researching a topic of value to the profession. Apparently, Howard Miller, a doctoral student at The Ohio State University in the late 1950s, was given the same advice. His 1959 doctoral dissertation was titled “PROCEDURES FOR IMPROVING THE USE OF PUBLICATIONS IN THE COMMUNICATIONS PROCESS BY PROFESSIONAL LEADERS IN AGRICULTURAL EDUCATION.” This dissertation resulted in the development of the Agdex filing system. Prior to working on his doctorate Miller had worked as both a high school agriculture teacher and as a county extension agent. He was familiar with the problem.

Miller’s study focused on analyzing how extension and agricultural education professionals used and managed the plethora of bulletins and other materials that came across the agents’ and teachers’ desks daily and then to come up with a plan as to how to deal with all these materials. He listed ten reasons why this research was needed. His final statement regarding the need for the study was (Miller, 1959, p. 14):

The value of materials which are received by the professional worker must be systematically stored and filed if they are to have potential use in educational programs. The Extension worker or the teacher of agriculture face a continual problem of processing and handling publications. Many regard it as one of their chief difficulties in conducting effective educational programs.

Of the four objectives for Miller’s research, the fourth was to (1959, p. 1) “Develop methods and procedures for more effective awareness, indexing, filing and use of publications by teachers of vocational agriculture and county extension workers.”

I would love to go into details about Miller’s research process, but space precludes that. This was an exceptional research study and involved professional librarians, the USDA, teachers, extension agents, and many others. Miller studied all the filing and indexing systems used in agriculture and in libraries and involved over 250 professionals in the research. Many of these 250 responded to surveys about what they used and what they desired in a filing system. The final indexing system was field-tested by 50 agents and teachers in Ohio. After the field tests, Miller reported that (1959, p. 310-311):

Teachers and agents evaluating the “AGDEX” system after orientation and use, gave general endorsement to the plan. Nearly three-fourths of the evaluators rated the system superior to currently used methods and 86 per cent indicated a willingness to adopt such a system. These data provided the conclusion that the method was functional, could be readily, understood and had appeal for potential users.

The Iowa State University Press saw the value of the Agdex system and commercialized it. They sold it using the titled AGDEX: An Index and Filing System for Agricultural Publications. It included a guide for use and color-coded gummed labels to apply to file folders. The first publication date was 1959 with a second printing in 1962. It sold for $4.95. A book review of the Agdex filing system appeared in the April 1963 issue (p. 222) of The Agricultural Education Magazine. See the review below.

Figure 1. Book Review of Agdex, The Agricultural Education Magazine, April 1963.

A survey of states in 1968 found that 16 states recommended the use of Agdex to their teachers. A resolution was passed by the Agricultural Education Division of the American Vocational Association in 1968 encouraging the use of the Agdex system. In part, the resolution stated (Ridenour, 1969, p. 248) “…each of the states not now using the AGDEX filing system be encouraged to adopt the system and to conduct workshops with their teachers concerning the use of the system.”

The Agdex system was refined and updated in 1969. Miller and his doctoral advisor, Ralph Woodin were listed as the authors. The sale of the Agdex system was then handled by the American Vocational Association (AVA) at the request of the Agricultural Division of the AVA starting in 1969. It sold for $4. A book review of the updated Agdex system was published in the October 1970 issue of The Agricultural Education Magazine. It said basically the same thing as the 1963 review. There may have been additional revisions and tweaks to Agdex since then of which I am not aware.

How Did Agdex Work?

It would be difficult to fully teach you how the system worked within the confines of this Footnote. However, I can give you an idea. The system has been tweaked over the years but the original version as envisioned by Howard Miller follows. First, the system was organized used 10 major divisions known as Subject Classes. They are shown in Table 1

Table 1. Divisions (Subject Class) in the Agdex System

Notation Subject Area Color-Key
100 Field Crops Green
200 Horticulture Pink
300 Forestry Buff
400 Animal Science Red
500 Soils Brown
600 Insects-Diseases-Pests Blue
700 Agricultural Engineering Orange
800 Agricultural Economics Yellow
900 Open for Expansion Gray
000 Agrelature—Related Agriculture White

Each major subject class was then sub-divided into 10 categories. And within those categories, there were further divisions. For example, in Table 2 below you will see 240 is Nut Crops. If you worked in an area with few nut trees, you might need only one file folder – 240 Nut Crops. Any material dealing with nuts would go into that one file folder. However, if you were in a nut growing area you might need additional folders for Almonds (241), Peanuts (245), Walnuts (246), etc.

And finally, there were 10 additional classifications for each category. So, two numbers were assigned to each item. If you were in an area that grew lots of walnuts, you might need folders 246/20 which would be walnut culture, or folder 246/30 walnut varieties. The Agdex system could expand as needed depending upon your local situation.

The Horticulture and Animal Science Subject Classes are broken out in Table 2. Other subject classes had similar divisions.

Table 2. Sampling of Sub-Divisions in the Agdex system

210 Tree Fruits 10 Management
220 Citrus and Sub-Tropical Fruit 20 Culture
230 Small Fruits 30 Varieties
240 Nut Crops 40 Breeding-Improvement
250 Vegetables 50 Harvesting
260 Specialty Crops 60 Storage
270 Flowers 70 Processing
280 Ornamentals 80 Products
290 Open 90 Open
410 Dairying 10 Management
420 Beef Cattle 20 Care and Husbandry
430 Sheep 30 Selection-Improvement
440 Swine 40 Breeds – Breeding
450 Poultry 50 Feeding
460 Horses and Mules 60 Feeds
470 Small Animals and Pets 70 Processing
480 Wildlife 80 Products – Utilization
490 Open 90 Open

During the heyday of Agdex many curriculum materials centers, extension agencies, and government documents would be printed with the Agdex number on them. Thus, one could quickly file the document. See Figure 2.

Figure 2. A bulletin with an Agdex number

As a Penn State undergraduate student, MeeCee Baker secured a work-study position as the student librarian in the Department of Agricultural and Extension Education’s resource room. She shared the following:

I loved this job and my obsessive-compulsive tendencies were well matched with classifying materials according to the AGDEX system. I always wondered why these were not done in alphabetical order. Howard Miller, who developed the system, must have been a plant science guy since the AGDEX started with field crops.

 I remember buying the color-coded AGDEX system to use in my teaching assignments, and if Krista Pontius and Mike Clark searched deep enough in the Greenwood Ag Department, they would probably find remnants of my classifying past. I loved AGDEXing all my materials. It gave me a sense of competency and maybe even control during my early teaching years. Assembling a complete AGDEX library was an important goal for me. Having all these materials organized and at the ready allowed me to feel like I had a resource for base-level competency across the agricultural genres.

Agdex Spreads

Even though the use of Agdex in agricultural education programs in the United States did not become wildly successful (that is my opinion), other countries adopted it. In Australia, the system was adopted (perhaps adapted) by the federal Department of Agriculture and used to classify their agricultural bulletins. Scotland started using Agdex for its agricultural advisors in 1973 and its use expanded to include students involved in agricultural education and training throughout the UK. The Canadian government also adopted Agdex and it is used widely today, especially in the province of Alberta. If you do a Google search for Agdex you will find numerous Alberta and Australian agricultural bulletins with Agdex numbers. Figure 3 shows the Beef Cow-Calf Manual produced in 2008 by the Alberta Agriculture and Food Ministry. The Agdex number 420/10 is printed on it. The 2004 Queensland (Australia) bulletin on Managing a Beef Business in the Subtropics has the 420/10 Agdex number printed inside the cover (Figure 4)

Figure 3. A Canadian bulletin with an Agdex number

 Figure 4. An Australian bulletin with an Agdex number

Concluding Remarks

If your filing system is a mess (or non-existent) this time of the year might be a good time to block out a few days and work on it. It will save time in the long run and make you appear more competent. If you are a teacher, you might consider having an FFA officer do your filing. I used Agdex as a high school agriculture teacher and was pleased with the system. It works. I had a basket for bulletins and other materials that needed to be filed. Once a week the chapter secretary filed the materials using the Agdex guide. The student enjoyed this task and felt valued. And it helped save me time.

I do not have any idea to the extent Agdex is used (or not used) today. It has not been on my radar screen in a while. Perhaps it is time to have an Agdex revival. With the advances in technology, it could be part of a digitally based filing system. I have a small scanner sitting on my desk and do a lot of electronic filing with it. Perhaps the revival of Agdex would be a great project for our professional societies or even an ambitious graduate student or professor to undertake. If you want to see what the actual Agdex guidebook looked like you can follow this link.

In case you are wondering whatever happened to Howard Miller, the answer is simple. After earning his doctorate at Ohio State in 1959 he was employed at Michigan State University with the Department of Information Services. In 1968 he moved into other administrative roles at Michigan State and retired in 1981. He spent a considerable amount of time thereafter in Florida. He died in 2012.

Figure 5. Howard Miller

What is the legacy of Howard Miller? He developed a filing system for agricultural publications that was widely used in the United States, Canada, the United Kingdom, and Australia. It is still being used today in many places.

What will your legacy be?


Iverson, M. J. & Jacks, L. (1976, September). A Filing and Materials Handling System. The Agricultural Education Magazine. Volume 49. Number 3.

Miller, Howard (1959). Procedures for Improving the Use of Publications in the Communications Process by Professional Leaders in Agricultural Education. Doctoral Dissertation. The Ohio State University.

Ridenour, H. (1969, April). AGDEX: A Filing System for Instructional Materials. The Agricultural Education Magazine. Volume 41. Number 10.