Gary L. Wagner

A.W.G. Farms Inc.

Route 1 Box 123

Crookston, MN 56716

(218) 281-7905

OVERVIEW

Global Positioning System (GPS) and Site Specific Farming: if these aren't household words yet, they soon may be. GPS Is poised to revolutionize today's farming methods. It offers for the first time a way to precisely measure your position anywhere on Earth and Site Specific Farming may become a more precise way to farm.

For years we have measured the characteristics of our fields. We have looked at parameters like soil composition, moisture levels, nutrient concentration, and crop yields, but have had no way to pinpoint the data to specific locations in the field. Field characteristics are not uniform over large areas, and in fact, would we like to study those characteristics right down to a resolution of a few yards.

In 1993 and 1994 we started to experiment with a yield monitor and GPS equipment to accomplish site specific information on our farm, I will cover the equipment used and information gathered in this two year period. I also will try to interpret some of the results, which at best, is an educated guess.

OPERATION

A.W.G. Farms Inc. is a small grain, sugar beet, and sunflower operation, located in the northern region of the Red River Valley of Minnesota; this is approximately 22 miles due east of Grand Forks, North Dakota. The farm principle operators are three brothers, Wayne, Daryl, and myself Gary. We farm approximately 4500 acres; 800 acres of sugar beets, loon acres of sunflowers, and the balance to Spring Wheat, Durum, Barley, and Soybeans.

The farms labor resources totalling 14 men during the peak harvest times, and 3~5 men during the spring and summer operations.

The term site specific farming' was a new term presented to us in the summer of 1993, when we were approached to use a pro-type combine yield monitor. P.C. Robert, of the University of Minnesota, St. Paul, contacted us several weeks before grain harvest, with the possibility of trying a yield monitor system. We accepted the invitation, and were introduced to Ted Macy of Application Mapping, Frankfort, IL.

Ted Macy is the principle software developer and owner of Application Mapping, that uses the GPS (global position satellite) system, grain yield monitor (Ag Leader 2000 from Ag Leader Technology, of Ames, Iowa), and computer, to generate yield maps. Ted came to our farm at the start of harvest to help us calibrate the yield monitor and complete the work on his software program.

We installed the monitor on the combine, a lap top computer in the cab, and GPS equipment both on farm and combine cab. The original thought was can oethis be possible but in a very short time we became believers.

YIELD MONITOR

The yield monitor has three major components; yield sensor, moisture sensor, and monitor control box. It has the capability to;

• Continuously measure and display yield, moisture, speed, grain flow, and acres covered per hour.
• Calculate, display and record average yield, average moisture, area, distance, wet bushels, dry bushels, harvest date and time for each load, as well as field totals
• Record field and load names.
• Records a total of 976 loads.
• At the season end, down load all information collected from the monitor during the season, to a computer, and then to paper.

GPS EQUIPMENT AND INFORMATION

The GPS equipment has three components'. satellite radio receiver, differential radio broadcast, differential radio receiver. The GPS system is a set of 24 satellites circling the Earth. They broadcast a precise set of radio signals and time references. The orbits of the satellites are designed so that there will be at least four in view over any one point on Earth at all times. A specially designed radio receiver detects these signals and, with its internal computer, measures the distance from itself to each of the satellites from which it receives signals.

Once these four or more distances are known, along with the exact point in space where these satellites are located, the receiver can calculate exactly where it is on Earth, usually within 300 feet. The error margin is due to several factors, mostly by the US Department of Defence (DOD), which controls the satellites. The GPS system is 50 accurate, and provides such good global coverage that the DOD decided to purposely induce errors into the radio signals to prevent foreign powers from utilizing this asset in times of war. Thus SA, (Selective Availability) was developed and it affects all civilian GPS receivers, and creates most of the 300 foot error.

This 300 foot error is not acceptable in a agriculture application, a more accurate form of GPS is need. Differential GPS (DGPS), was developed to over come this problem. In DGPS, a GPS receiver sits still at a known location and continually measures its position based on the signals it receives from the satellites. Since it knows it is sitting still, all measured positions occur inside a 300 foot circle, and are recorded as an error to the actual position.

This error is then broadcast on a radio to a separate GPS station on the combine. That unit measures its position according to the satellites, applies the error signal sent from the reference station over the radio link, and can fix 'Is position in the field to with in a foot.

Ted Macy's job was to tie the two technologies together. The GPS information and yield information from the yield monitor are combined and stored on a computer disk to help generate accurate crop yield maps.

SUGAR BEET YIELD SENSOR

In our operation, sugar beets is the major cash crop. All resources are focused on raising the best possible quality crop. Unlike a yield monitor for a combine (small grain industry), the sugarbeet industry is minute. Developing a yield sensor for this type of harvest machine has to come the Industry itself.

In 1994 Vern Holirnan, Extension Ag Engineer, North Dakota State University, approached us to develop a yield sensor for our sugar beet harvester. Vern received a grant from the Sugarbeet Research and Education Board of Minnesota and North Dakota, to work on this project.

A proto-type sensor was built. May obstacles needed to be overcome, especially how to control the vibration produced by the machine. Vern was very successful, and is planning to work with industry to further develop the sensor.

In cooperation with other individuals that are working on sensors for potatoes, this sensing technology will soon be a reality.

DATA ANALYSIS

For this presentation I will use one field and attempt to analyze the information that we gathered for the two years. Some of the tool used:

• Grain yield maps (2 yrs)
• grid soil test information (2 yrs)
• soil types maps
• topographical map

OTHER BENEFITS

Besides gathering information on yield information other benefits are;

• Spot a device that works In conjunction with the yield monitor and GPS system to record problem areas such as;

l. weed problem areas

2. drainage problems

3. rock piles

4. or any other field problem areas

• With GPS soil test locations can be recorded to repeat fertility test.
• With both the Grain Sensor and Sugarbeet Sensor we will have the ability to determine the amount of weight stored on a truck. This will help to maintain "legal truck weights for road conditions.
• Determine the need for Fertilizers and chemicals. Hopefully will reduce the overall input costs.

Other benefits can be achieved by using your imagination.

SUMMARY

For many years industry indicated that computers will make farming more profitable. Up to this time this was not true. If the farmer had an accounting back ground he could do his own financial record keeping, saving the price of an accountant. But all information had to be typed into the computer via the keyboard. Finally, we can obtain useful information about our farm "on the fly or at the same time we are doing our work. This new technology will greatly increase our knowledge of the land we farm. But the more we know, the more ~ Crop consultants or people specializing in interpreting this information will be needed. The future is beginning NOW, are you ready??