hen humans first learned to till the soil and plant seed, they probably looked to the heavens for signs that their crops would do well. Today, farmers are still looking skyward, but today they are looking to satellites for aid in growing their crops.
A network of satellites known as the Global Positioning System, or GPS, originally sent into space by the military, is increasingly being used by farmers to make better decisions about how they grow their crops. The GPS is a central element in what has come to be known as precision farming.
The GPS is also an integral part of the College of Agriculture and Life Sciencesí new Geographic Information Systems (GIS) Education Laboratory. The Williams Hall lab contains the hardware and software necessary to practice precision farming. Dr. David Crouse, a North Carolina Cooperative Extension Service specialist in the Department of Soil Science, is coordinator of the new lab.
The 21 high-end workstations, software, GPS receivers and other equipment that are the heart of the lab are being used by students to learn how to use the technology. The first class was taught in the lab in the fall of 1999. Crouse points out that graduates with GIS skills will be in greater and greater demand as the technology becomes more widely used.
Adds Dr. George Barthalmus, director of Academic Programs in the College, "This lab is a wonderful investment and a perfect example of how a department can bring state-of-the-art technologies to its undergraduates."
Precision agriculture begins with the GPS, those satellites. Crouse says there are 27 orbiting the earth (24 active, three reserves). He explains that the satellites emit electronic signals that may be picked up by a receiver on the ground. There are usually eight to 10 satellites in view at any given time from any given spot on the earth. The signals from these multiple satellites may be used to determine within a few feet the position on the earth of the receiver. Thatís all the GPS does, determine with great accuracy the position of a receiver on the ground.
A second, equally important element makes precision farming possible ó the GIS computer software that makes use of GPS and other data. A farmer may, for example, use a GPS receiver to record a number of positions in and on the boundary of a field. This information may then be downloaded to a computer equipped with GIS software. The software produces a highly accurate map of the field. If another "layer" of data is then added ó soil test results from the field, for example ó the software will produce a map of the field showing, usually with different colors, the condition of the soil.
If a GPS reciever has been used to note the precise locations in the field where soil samples were taken, the map that results when the data from these samples are incorporated will provide a picture of soil conditions from location to location across the field. Farmers who do not use GPS and GIS technology may take several soil samples from a field, but the data from the samples are usually averaged to give a uniform fertilizer or lime recommendation for the field. Precision farming technology tells a farmer whatís going on in each part of a field.
Armed with such knowledge, a farmer may then take into account the different needs of the soil in different parts of a field and apply fertilizer or lime according to those needs. Variable-rate fertilizer applicators equipped with GPS receivers are now available. As the applicator moves across a field, the receiver notes its location. At the same time, an onboard computer equipped with GIS software notes soil conditions at that location and applies fertilizer accordingly.
Data on crop yield may also be added to the mix. Combines equipped with yield monitors and GPS receivers can record yields at numerous loca-tions as the combine moves through the field. The yield information then becomes yet another data layer, showing on a map where and how yield varies across the field.
Precision farming can save farmers money by allowing them to maximize yield while minimizing fertilizer and other applications, says Crouse. The technology can also help farmers protect the environment.
"If a farmer is putting out nitrogen when itís not needed, odds are it will end up where we donít want it," causing possible environmental damage, Crouse explains. Indeed, environmental concern is part of what is driving the adoption by farmers of precision agriculture.
Yet the software and hardware necessary for a farmer to practice precision farming are expensive, and itís not always clear that the savings a farmer may realize from cutting back on nitrogen applications will pay for the sampling and computer time necessary to determine the precise amount of fertilizer to apply. That, says Crouse, is part of the reason the GIS lab was established.
Precision agriculture technology has become available over only the last 10 years or so, he explains. It is not yet clear exactly how best to use the technology. Using the new lab, College scientists can do research that will help farmers make the best use of the technology.
"Weíre looking for the best data layer at the best price," says Crouse. "Thatís where research is going. Whatís the best way to sample? Whatís the most economical spacing? The people who figure out how to use this technology in an economical way will be on the cutting edge."
Establishment of the lab was made possible by a gift of computer software, training, technical support and equipment valued at $460,140 from Agronomy Service Bureau, a subsidiary of Farmland Industries, which sells precision farming software and equipment. Other funding for the lab came from N.C. State University Educational Technology Funds, $85,500; the Collegeís Academic Programs Office, $40,000; the Cooperative Extension Service, $24,500; the Department of Soil Science, $8,000; the North Carolina Agricultural Research Service, $77,000; and a U.S. Department of Agriculture Higher Education Challenge Grant, $80,000.
The lab is being used for workshops designed to bring extension agents and other professionals up to date on precision farming technology. And while it isnít yet clear exactly how the new technology will fit into American agriculture, it does seem likely that at least some elements of GPS and GIS technology will be a part of the American farm well into the future.