Getting the lay of the land

By Alan Sorensen

They call it precision agriculture. It's the way farming is done in Midwest states like Iowa and the Northwest of Washington and Oregon.

Now it appears ready to make its debut in Montana and along the Hi-Line.

Chad Minteer of Electronic Data Solutions was on the MSU-Northern campus Wednesday to explain how GPS (global positioning systems) and GIS (geographic information systems) are enhancing producers' understanding of their land.

With the use of a handheld GPS receiver, a farmer or rancher can map out his entire property. The receivers use signals from up to 24 satellites at just one frequency to produce latitude, longitude and elevation readings.

Minteer's company focuses mainly on natural resource, water and forestry conservation programs. The handhelds are waterproof and temperature rated to function in temperatures between 0 and 140 degrees Fahrenheit.

Minteer explained that the higher the grade of the receiver, the more precise the measurements.

Navigational grade receivers have the least precise readings that put the user within a horizontal area with a variable of between one to five meters. The mapping grade receivers put the users within a foot or two of horizontal location.

Besides being more accurate, mapping grade receivers can record more scripted information, such as locations of utility poles, city streets and county roads. They are used regularly for natural resource management, utility management and asset management and cost between $3,500 and $12,000 per system, Minteer said.

Their only draw back in city and other uses are their dependence on satellite signals. GPS receivers are useless among tall buildings where the signal from the south is blocked. They are useless, too, in canopied and underground work areas.

GPS receivers are particularly fit for mapping open fields and even in forested areas. The U.S. Forest Service is in the process now, Minteer said, of mapping all of its roads. Any students familiar with GPS and interested in summer work should contact the Forest Service about employment.

The most precise receiver today is the survey grade receiver. At a cost of up to $50,000, the survey grade receiver has an accuracy discrepancy of less than 5 centimeters. It's reading can be as accurate as one millimeter from true.

All of the receivers are more accurate horizontally than vertically. The elevation measurement will generally vary about two to three times more than the horizontal, Minteer said.

Because the satellite readings can be skewed by lapses in signals or other variables, secondary sources can be used to bring the readings to the right location. One method is a ground-based beacon and the other is a satellite differential source.

Ground-based beacons are provided by some government agencies, such as the Coast Guard. In June, he said, a Billings beacon station will open.

"You can map in a section corner in the middle of nowhere (with a handheld GPS)," Minteer said. "You can get back within a foot of it (using a handheld GPS)."

What a group of Hill County producers hope to do in the near future is hook up satellite receivers that can pickup satellite photographs. Minteer said it is possible to map out a person's property with GPS systems and then produce a grid work on a computer program. The satellite image can then be downloaded onto the farm's grid.

The landowner can then look at the photograph of his property and spot something as small as a foot square discoloration.

Precision agriculture producers use GIS to map their fields, crop types, acreage, crop histories and soil types. Minteer said producers can plug their ag receiver into a yield monitor and get records year after year.

Field mapping and yield monitoring leads to precision agriculture. A producer maps out his entire property and inserts soil types for each square inch or foot. When pulling his fertilizer dispenser around the field, the computer system on his dispenser will read signals from the satellite to let it know where it is at all times. The dispenser will then be triggered to dispense the appropriate amount of fertilizer at each spot.

The computer system will also let the producer know what grade of fertilizer, pesticide or herbicide is needed in each location. It can also tell him how much water is being retained at each location and how much more is needed.

Minteer told the group of engineering and ag students attending his afternoon session that in their fields, "it helps to know about GPS."

Mike Zook, Farm Services Agency executive director in Hill County, said recently that Hill County could be one of the first counties in the United States to have GPS mapping for all of its agriculture land.

"NRCS has been working with it for quite some time," FSA Executive Director Mike Zook said. "We are excited about it. We are told that Hill County is one of the high priority counties for implementing this technology."

The technology Zook referred to is the global positioning system that enables users to determine their exact location on the planet, including their elevation. In this case, plans call for an entire county map to be layered. The result would be a topographical map that provided an extremely fine details of nearly every inch of land in the county.

"It would be digitizing farmers' maps and layering that information on the basic aerial photograph," Zook said.

The map would provide producers and conservationists with information regarding everything from soil content and spots susceptible to saline seep to weed infestations and pooling water.

Zook said GPS could begin in Hill County within two or three years, but not until it is determined to be economical and feasible.

"The USDA is the record keeping agency for all farms in the United States," Zook said. "The USDA is concerned with the efficient use of its money and the best interests of the farmers."

Zook said that walking every inch of the county with a handheld receiver is not the only way to do GIS mapping.

"That's one way," Zook said. "What we're going to do is take the new (aerial) photographs and digitize those. We're going to be basically using that kind of imagery."

Zook said the photos could be taken either by airplane or by satellite. Once the photos are taken, they will be sent to regional centers, digitized, and sent back to the counties, he said.

Zook added that the Chippewa Cree Tribe at Rocky Boy is already deeply involved in GIS mapping.

Yesterday and today, dozens of departments and staff on Rocky Boy's Indian Reservation are participating in Earth Day Two activities with Rocky Boy and Box Elder school students. Among the things the students are being exposed to are the benefits of GIS mapping.

Jay Eagleman, tribal water resource manager supervisor at Rocky Boy, was among the tribal team members who successfully worked out a reserved water rights compact with the state and federal governments. Today, he and his staff, including Bernadine Wolfchild, data collections officer, are mapping the entire 122,259.060 acre reservation.

"We are using it as a planning tool," Eagleman said. "We have just purchased an Arch-Info system, a stand-alone type of system that will allow us to map our entire infrastructure and add to the current thenes and layers that are currently available to the tribe. Also it will allow us control over the information pertinent to or in anyway relevant to the Chippewa Cree Tribe."

GIS mapping was one of the items the Tribe identified in its rural, municipal and industrial feasibility study that the water resource department will be administering, Eagleman said.

Tony Belcourt of Natural Resources at Rocky Boy said his department is actively involved in GPS and GIS mapping, too. He said that Wolfchild at water resources is coordinating data collected by natural resources personnel, too.

Belcourt said the information Natural Resources personnel collect from satellite imagery is nearly instantaneous and very accurate.

"There are 11 satellites in the atmosphere and the signal we read comes off of those and into our laptop computers and gives us accuracy into within a foot of where we're at," Belcourt said. "We're doing prescribed burns, noxious weed infestations, we just completed some range unit fence lines, our range units.

"We're doing our timber thing and future planning sites, and we're doing brush clearing sites."

Belcourt said workers can go into the field, collect data on the receiver, come back into the office and download that information into their computers. The workers can then pull up the layers already in the computer and add the new information to produce a map.

Belcourt said the technology Rocky Boy is using is far advanced over anything FSA is currently using to construct its maps.

"Ours are so much faster and more accurate," he said.

Belcourt said he really enjoyed the Earth Day events at Natural Resources Thursday. Personnel showed students in grades 6-12 the GIS system and forestry products, and tribal elders spoke with them.

"It was pretty interesting."