Re: Crop yield mapping

In article <786320702snz@jegs.demon.co.uk> Julian@jegs.demon.co.uk (Julian Swindell) writes:
Dear All,
>        Our College has been collecting crop yield data for two years,
>using satellite navigation techniques to locate the positions of the samples,
>which are collected during the harvest. This data is being analysed in a
>geographic information system (GIS) in order to create yield maps of the
>fields, showing the spatial variation in the yield levels. I would be
>interested in hearing from anyone who has been workng in this area, which is
>often referred to as "precision farming". I am particulalry interested in
>problems relating to the accuracy of the yield data,  the influence of the
>speed of the combine on the yield measurement and the influence of the pattern
>of the harvest on the apparent distribution of the yield variations.

I have just started the Precision Farming Group under the Institute of 
Agricultural Engineers, where (I hope) we can create a forum for discussion on 
yield mapping and other issues.

We are hosting the inaugural meeting here at Silsoe College, Cranfield 
University on Wednesday 14th December at 2:00pm. All are welcome.
There will be a number of people who are developing yield mapping 
technologies, myself included!

If you cannot make the meeting then drop me an email and we can take it from 

There is another group in the States headed by Pierre Robert at the University 
of Minnesota. He can be contacted as PRobert@soils.umn.edu

I hope to publish the proceedings of the last Precision Farming Conference on 
WWW in the next month or so. Watch this space.

    | Eur Ing Simon Blackmore                     |
    | Lecturer in Information Technology          |
    | Silsoe College                              |
    | Cranfield University                        |
    | Silsoe                                      |
    | Bedfordshire                                |
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    | England                                     |
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Subject: GPS and Prescription Agriculture
Date: 21 Jan 92 14:48:09 GMT

Background:  Prescription agriculture is a method of farming where instead
             of seeding/fertilizing/spraying the same amount over an entire
             field, an amount appropriate for the slope and soil is applied.
             This can be done by mapping the field and then using the map
             to guide application.  A key difficulty is in knowing where the
             tractor is on the field.  The global positioning system (GPS)
             uses an ensemble of satellites sending coded information to
             triangulate the latitude, longitude, and altitude of a receiver
             to within a few feet. GPS receivers are down to about $1500.

Question:    Are there any Prescription Agriculture GPS papers in recent
             conference proceedings or journals?  I am aware of only one
             project in this area and it is being done by a farmer in