A Look into Yesteryear on the Origin of the Phrase

"Site-Specific Farming"

 

Editor's Comment

 

Years before the first commercial yield monitor was available, a group of Purdue scientists were discussing and developing an alternative form of farm management. "Site-specific" farming was presented by Howard Doster of Purdue Agricultural Economics at the "Purdue On-Farm Computer Conference - November 21, 1983". This often debated phrase, was being used at Purdue three years before the famed AgChem VRT Ortlip patent, which was issued in 1986.

 

The following paper provides an interesting look at site-specific farming plans seen through the eyes of Purdue researchers in the early 1980's. It is useful to compare current and past theories surrounding this once novel idea and its reality today.

 

Greg Blumhoff, SSMC Information Systems Manager

 

 

Computer Assisted Big Ten Crop Farming

 

Howard Doster, Robert Nielson, Sam Parsons, and Tom Bauman

Purdue On-Farm Computer Conference, 1983

 

Introduction

 

How would you like to increase your net income, say $10.00 per acre?  Suppose this is possible if only you do a better job of selecting and applying your fertilizer, seed, chemicals and tillage according to your soil type.  To do this better job, suppose you must:

 

First, determine your soil types.

Second, determine your in-field location "on the go" as you travel across your fields.

Third, be able to locate each soil type as you travel across your fields.

Fourth, be able to switch rates and perhaps even varieties "on the go" as you apply fertilizer, seed, or chemicals and switch tillage methods as you move onto a different soil type.

Fifth, be able to measure crop yield and moisture content "on the go" so as to identify your actual yield by soil type.

Sixth, collect weather information at several locations on your farm.

Seventh, identify and record disease, week, tillage or other stress agent by site found.

Eighth, submit your input-output data to a central data bank where your results will be compared to the results other farmers obtained on the same soil types with different weather.

Ninth, receive statistically significant input-output relationships from a central data bank describing what happens on each of your soil types when (a) farmers use the same practices as you but experience a range of weather situations and (b) farmers use various other production practices and experience a range of weather situations.

Tenth, select and carry out the best combination of practices for your farm.

 

We are gathered here today at a computer conference.  I assume we all feel a computer might somehow improve our information and skills.  This is the third year your committee has developed a program for crops and machinery.  We have done considerable dreaming.  We have also searched the country to see what others are doing.

 

I think it is fair to say that many persons went away from our first session two years ago dissatisfied.  We did not present them with any computer programs that would immediately make them healthy, wealthy or wise.   In developing that first session, your committee did conclude that a computer could be used to store, retrieve and interpret crop information.  Your committee also concluded this information should be site specific.  Because crops responded differently in different soil types, records should be kept, plans should be made, and performance should be carried out for each soil type.  A method for identifying and storing information by 1.3 acre cells or sites was presented.  The cell size and location was intentionally set to coincide with the current USDA "about to be computerized" soil map files for Indiana counties.

 

In 1982, your committee set out to determine how farmers and others were using computers for crop and machinery information.  Apparently, not many people were using their computers for this purpose.  We did find persons who were using their computers to file crop input and output information by field and by landlord.  We found persons who were recording machinery repairs by machine.  However, no one was very excited about what he or she was doing.  The records were no different than "by-hand" systems.  While they did provide a document that the events occurred, the information was not being used for any exciting purposes.

 

In spite of the limited immediate usefulness of the material presented, the session last year was perhaps the most exciting session I have ever moderated!  Why?  First, the speakers and the audience came to realize the limited value for decision making of one person's performance records.  So what if a person keeps account of his inputs and outputs on a field?  The field contains different soil types, the weather and other stress will not be repeated, and new inputs will appear on the market.  So what if a person keeps account of tractor breakdowns?  Of what use can he make of the information?  He has only one or a few tractors.  Since he didn't know it was likely to need an engine overhaul at around 2500 hours, it didn't occur to him to have the job done in the off season just ahead of this expected occurrence.

 

Why was last year such an exciting session for me?  I helped introduce many persons to probability theory and statistical inference as procedures for drawing conclusions about what happened and what will happen in the future!  Given a large number of observations, the probability of specific responses can be estimated.  Farmers can use information from similar farming situations to make better decisions for their own farm.

 

We even had a spontaneous joke.  Someone asked our seed corn company representative speaker whether the yield of a hybrid with a test plot yield of 194 bushel/acre was statistically different from another company's hybrid which yielded 192 bushels.  Our speaker's response -- If my hybrid yielded 194 bushels, it's different.  If my hybrid yielded 192 bushels, there's no statistically significant difference between them!

 

Given the apparent randomness of weather events and the continued introduction of new input alternatives, your committee feels that farmers would improve their management skills tremendously if they could more easily measure their own input-output performance, compare it with the performances of other farmers with the same soil types, and, by statistical inference, select the best corn or other crop growing processes.  Computerized measurement and machinery control, information storage, retrieval, and interpretation may make this improvement in management skills possible.  Let me explain how this might be done.

 

 

TYPES OF INFORMATION AND SKILLS NEEDED

 

 

What Makes Corn Grow?

 

  1. First, a farmer must know "What makes corn grow"!  He needs to know the input-output relationships for the many possible ways or recipes for growing corn on each site of his farm.  That is, he needs to know what yield he will get for each combination of variety, fertilizer, chemical, tillage, plant/harvest date, etc., he might select.  He needs this information for each of the weather years he can expect to experience.  There is no good substitute for this knowledge.

 

A farmer must know what is "supposed to happen" for each recipe before he can select the recipe he wants to happen.  Further, after he is carrying out a recipe, he must know what was supposed to happen before he can decide if it is really happening or if the crop is "sick".

 

Which of the many possible recipes for growing corn is most profitable for each site on his farm?  This question will never be completely answered.  Yet, each of us will continue to try to get a better answer.  How will we do that?  We will collect information that is more precise as we attempt to determine what is happening on each site each year.

 

To really do this, we must:

a.     inventory the soil characteristics of each unit (say, acre) of our farm.  These characteristics include: fertility, water holding capacity, pH, trafficability, etc.

b.     measure and record weather; i.e., identify the temperature, rainfall, evaporation, etc.  Rainfall in particular should probably be measured separately at many sites on each farm.

c.     measure and record the date and amount of each input and each crop yield and crop moisture content for each acre.

d.     identify and estimate yield effect of each disease, weather stress, or stress caused by some poorly carried out production practice.

 

No single farmer, or no single research for that matter, can expect to experience all the likely weather or disease stresses on his own sites and no one person will grow more than a few of the possible recipes for growing corn.  Farmers, university researchers and farm input suppliers now share their experiences.  This experience sharing business would be much more helpful if the information handling procedures could become more standardized.  Your committee members are currently considering how to do that.  We have a felt need for standardized information collection storage, retrieval, exchange and interpretation procedures.

 

With better information handling procedures, we expect to get more useful information.  We then expect to more precisely predict what is supposed to happen when a particular recipe is grown.  We also expect to use this information to signal when a plant is "sick", i.e., not performing as expected.

 

How Do You Grow Corn?

 

  1. Second, a farmer must know "How to grown corn."  Once he picks a recipe, he needs to be able to carry out his plan.  There is no good substitute for knowing how to drive a tractor, calibrate a sprayer, or adjust a combine.

 

Further, when performance is different from expectations, he needs to be able to identify and separate weather effects, disease effects, and the effects of his own unusual performance.

 

Being able to get the job done is certainly a necessary corn growing skill.  Once a corn growing recipe is selected for each site, a farmer must carry out the various tasks of tilling, fertilizing, planting, observing for and controlling pests, and harvesting the crop.

 

First, a farmer must identify each site on his farm and find each site as he performs tasks on adjacent "sites" in the same corn row.  When he can do this, he can consider a new level of performance for his corn growing tasks.

 

We know that the best recipe for one soil type is often quite different from the best recipe for other types of soil located in the same field.  Tillage, fertility, planting rate, perhaps even variety, herbicide type and/or rate, could be different.  Often, it is costly to make "fields" out of each soil type.  Turn rows yield less and turning takes time.  Therefore, methods for controlling application rates, adjusting rates "on the go", and recording rates applied offer the potential for greatly enhancing a farmer's corn growing skills.

 

Equipment for measuring and recording crop yields and moisture content "on the go" by site is a part of this needed technology.  Other equipment for improving a farmer's corn growing skills might include process changing devices such as on/off switches, and devices for changing planting depth, press wheel tension, header height, ground speed, cylinder or fan speed, concave setting, etc.

 

How Do You Grow Corn Profitably?

 

  1. Third, a corn farmer must know "How to grow corn profitably."  He needs to use the above information to select the most profitable recipe before he purchases inputs.  In addition, as surprises occur because of weather, disease, his own production performance, or prices, he needs to switch to the new most profitable recipe.  There is no good substitute for these skills.

 

Presumably a farmer wants to select a recipe for corn or other crops for each site that will make him the greatest net return to his total set of resources.  Since he won't be able to plant or harvest all his sites on the same date, he will want to consider recipes for some sites which are based on "less timely" operations.

 

As stated earlier, no one farmer can expect to get all the corn or other crop growing information he needs if he relies only on his own experience.  However, if several farmers and researchers were to use a well developed and standardized information collection, storage, retrieval, and interpretation system, a farmer could more quickly discover likely recipes by using statistical inference procedures to compare the results from the recipes used by the other farmers with similar soil but different weather and other stress.

 

With a large number of persons supplying similar information a farmer could (a) learn the likely consequences of growing corn by his recipe for several different weather situations and (b) learn the best recipe used this year for several different weather situations for each of his soil types.

 

Summary

 

Earlier, we asked if you would like to increase your net income by $10 per acre.  We think that's reasonable estimate of the benefits you could realize if you had the crop management and control system just described.  In various ways, computers will be used to perform many of the jobs in this system.  Please help us improve the ideas and implement the practices.

 

Actually, you and your neighbors are already using many parts of this system.  We have asked some of them to tell us what they are doing.  We will spend the remainder of this session visiting with them.

 

End

 

Editor's Comment

 

Why is this material significant? The plan outlined in the presentation is as sound today as it was 18 years ago (pretty unusual, wouldn't  you say?).

 

We will end you with an insightful quote:

 

" What has been is what will be, and what has been done is what will be done;

    There is nothing new under the sun."  -- Ecclesiastes 1:9.

 

                              -- Greg Blumhoff, SSMC Information Systems Manager