University researchers and agribusinesses have been looking at precision agriculture too narrowly and missing its real potential, according to a University of Wisconsin-Madison expert.
“Initially, we”ve been using precision ag to manage fertilizer on cash grain crops,” says Peter Nowak, who studies farmers and their adoption of new practices. “That”s using $70,000 worth of technology to manage a small fraction of farm inputs.
“When many promoters of precision ag see that some sites within a field have lower nutrient levels, or hold less water, or have more pest problems, they immediately move to the logic of how to adjust the inputs in response to that variability,” Nowak says. “Perhaps the critical question is why this variation occurs in the first place and to what extent we can manipulate it. Explaining variation is only the first step. The real payoffs will begin when we can manage the causes of that variation.”
The recognition that yield can differ drastically within a field spurred the growth of precision agriculture. A field with an average corn yield of 150 bushels per acre, for example, may contain some areas that yield only 50 bushels and others that yield 250 bushels per acre.
“We”re learning about ecological differences in fields that occur over a few yards rather than acres,” says Nowak, a rural sociologist in the College of Agricultural and Life Sciences. “The average size farm today is the size of four farms just a few generations ago. So we face variation from field slope and soil differences as well as variation that traces back to how different farmers managed a field.”
Precision agriculture – or site-specific management, as it is sometimes called – involves a new set of technologies that will help scientists and farmers understand this variability. Ultimately, experts believe it will allow farmers to respond to that variability in ways that increase profits and reduce environmental problems.
Precision ag incorporates several sophisticated and expensive technologies – sensors that detect yield, soil moisture and pest problems; global positioning and geographic information systems to accurately map changes within fields; computers and computer programs to keep track of all this information; and farm machines that can alter inputs yard by yard across a farm field.
Nowak cautions, however, that precision ag is not like other technologies farmers may have adopted in the past.
“Farmers can”t just plug this product into their current management plan, as they might do with a new herbicide or seed variety, and see instant benefits,” he says. The value of precision ag comes when farmers can properly interpret the information it gives them.”
The idea of precision ag is intuitively appealing to farmers, according to Nowak, who has published several articles on the technology. His most recent article is an 85-page review paper with Michigan State University crop scientist Francis Pierce in the June 1999 issue of Advances in Agronomy. “Farmers find precision agriculture appealing because it strives to do the right thing in the right place at the right time and in the right way,” Pierce says.
Nowak believes that farmers are drawn to precision ag because of its potential. “Adoption is being driven by a belief that the technology will be valuable in the long term when the science catches up and can help interpret the variability,” he says.
Farmers should approach precision ag like any other major investment decision, according to Nowak. However, they need to realize that precision ag will require more of their time and effort as managers than most new technologies, because it is still developing and because farmers in many parts of the country may not have access to adequate support services.
“This is not a technological package for the ”Lone Rangers” out there,” he says. “Any farmer considering this investment should check out dealer and consultant support services, and see if other farmers in the area are using some or all of these techniques.
“Begin by investing in yield monitors,” Nowak suggests. “Depending on the yield variation you observe over several crop cycles, decide whether future investment is justified. Farmers with the greatest amount of variability within their fields are more likely to benefit than those with little variability. Another option for farmers is to see if any precision ag techniques are available on a custom basis in their neighborhood.”
Even where it has been most successfully applied, precision ag is only approaching a third of its full potential, Nowak estimates. “The technology”s critical impact will be in going beyond what is happening in fields to a better understanding of what affects crop performance,” he says. “Precision agriculture”s ultimate success depends on applying it to crops to manage variability not only within fields but also in cooperation with many neighboring farms over the growing season.
“In general, the benefits are limited when farmers just use it for managing crop nutrients,” Nowak says. “Many more benefits will emerge when it can help us manage pests, diseases, and crop quality across space and time. These are the scientific frontiers of precision ag today.”
Several of the technologies are still poorly developed, Nowak says. “Precision ag must evolve from a collection of partially compatible technologies to an integrated management system. There needs to be more work on developing better sensors, more data on environmental variability, and research that relates these two to yields. Researchers also must develop more models that can predict changing conditions during the growing season.”
“Farmers need products and tools developed specifically for precision ag. If precision ag is to achieve its many promises, researchers and marketers need to change their approach to issues,” Nowak says. “The machines, products and management styles of modern production ag have been built up in such a way that they are not able to respond to variance in the field environment.
“Most farm inputs used in precision ag today are unchanged from those developed to suppress ecological variation across a broad range of farm conditions. We developed nutrient formulations and tillage instruments to work on many kinds of fields,” Nowak points out. “Herbicides were created to be broad spectrum; label rates are designed to give a uniform response across a broad range of conditions. Seeds were bred for uniform response under a wide range of growing conditions. Our decision aids enhance farm management, not field management.
“Most of our current technologies come from a mindset of suppressing variation and minimizing differences across the environment. Then we use these tools with precision ag to improve productivity and wonder why we don”t see bigger returns.”
The research was supported by state funding to the UW-Madison College of Agricultural and Life Sciences.