Centuries ago farmers commonly tended small plots of land, paying attention to the needs of individual plants and growing whatever clearly did best in particular areas. But this changed as farm operations grew larger and more complex. No longer able to tend to the unique needs of plants and soil on every square foot of their land, farmers began to rely more on machines and standardization for soil preparation, watering, fertilizing, and pesticide application. 

While this approach has vastly boosted yields overall, it also revealed that productivity within fields is variable: Some sections produce higher yields because of variations in soil, drainage, sunlight, slope, and other factors, necessitating differing amounts of water, fertilizer, and other needs. To remedy that, an increasing number of farmers and other agricultural producers are turning to precision agriculture. Perhaps more accurately named site-specific agriculture, precision agriculture is the strategy of using the right management practice in the right location at the right rate at the right time. 

Determining all of those variables takes tools, so farmers use information technologies, such as global positioning systems (GPS), geographical information systems (GIS), and remote sensors such as satellites and aerial robots—commonly called drones—to customize how they address variable field conditions. Examples include using drones and ground robots to gather data to create detailed maps and identify problem areas, diagnose pest problems and nutrient deficiencies; equip tractors, combines, and harvesters with GPS to aid in planting in a straight line without overlap, applying fertilizers and reducing fuel waste; and using sensors to tell equipment when to spread manure, fertilize, and water at variable rates depending on the data that is gathered. 

The University of Minnesota’s Precision Agriculture Center has been a leader in precision agriculture research for more than two decades. Founded in 1995 by Professor David Mulla and the late Pierre Robert, professors in the Department of Soil, Water, and Climate, the center was the first of its kind in the world. Researchers continue to conduct studies on farms nationally and internationally while also developing innovative techniques for precision crop monitoring and management. 

Robert was the Center’s director until his death in 2003, when Mulla became director. Robert and others from the department recruited Mulla to come to the U from Washington State University, where he had been studying precision agriculture since 1984. “I’m one of the early pioneers of precision agriculture,” Mulla says, recalling how in the 1980s he began noticing a connection between variability across landscapes and crop yield. “I could see that crops didn’t perform as well in areas with light-colored soil, particularly on steep slopes, and I wondered why there was so much variability and how we could manage fields more effectively.”

Used properly, precision agriculture helps farmers get the most value and productivity from every inch of land. It also may help minimize agriculture’s environmental impact by reducing waste, conserving water and energy, and reducing potentially harmful runoff containing pesticide and herbicide. Currently used primarily in the production of crops such as corn, sugar beets, potatoes, wheat, barley, oats, and soybeans, precision agriculture researchers are studying ways to expand the practice to include the management of vineyards, orchards, livestock, and more. 

 The University’s multidisciplinary research team remains one of the most robust, crossing three colleges and numerous departments. Mulla’s research focuses on several areas, including groundwater and soil quality management, as well as the use of drones to estimate yields and detect plant diseases and nutrient deficiencies in farms and orchards. 

In the field

Todd Golly (B.A. ’95) had two passions while studying agricultural engineering at the University of Minnesota: agriculture and technology. Seeing firsthand how precision agriculture could change farming, he worked as a consultant for the University’s Precision Agriculture Center after graduation. In 1999 he returned home to Winnebago, Minnesota, and helped turn his family’s 6,000-acre corn and soybean farm into an early adopter of precision agriculture. “We were among the first to use precision ag to control variable-rate spreading of fertilizers, turn sprayers of herbicides and fungicides on and off, sample soils, monitor yields, and auto-steer equipment,” he explains. 

“Everyone wants to be more efficient,” says Golly, who believes the technology he’s using is giving him an edge over other farms. GPS sensors on combines, for example, automatically shut off sprayers if the machine heads into an area that’s already been treated. “That’s hard to do just by looking, so it’s easy to use too much herbicide or fungicide because you don’t want to miss an area,” he says. 

Auto-steer on tractors and combines makes the farm about 25 percent more productive, Golly figures, because the technology prevents overlapping passes for things like tillage and harvesting and allows work to continue after dusk. Also, drivers who are on board to make sure the equipment functions correctly are freed up to do other tasks such as going over budgets or other data. 

Convinced that precision agriculture is the future of farming, Golly also runs Aker (formerly known as Leading Edge Technologies), which he cofounded in 2013. In addition to drone-based services, the company offers a wide range of technology for agricultural and other industries. “Precision ag is one of the few growth areas in this industry,” he says. “We’ve been adding new technologies for years and we’ll continue to add more all the time.”

Shakopee, Minnesota-based Farmers Edge also offers a wide range of customized services to farmers nationally and around the globe. Jose Hernandez (Ph.D. ’07), a former student of Mulla’s, was hired there in 2015. In his position as a regional agronomist he uses a lot of the science he helped develop at the University to help the company with research and product development. He also works directly with clients. 

“Growing up in Costa Rica, I always loved working with numbers and statistics, and I started studying precision agriculture because I liked the quantitative approach to farming,” he explains. “Farmers want to maximize yields, and all of the data we collect helps identify variability in the fields so we can obtain the highest yields and avoid over-application of inputs like fertilizer and water.”

Hernandez likens the concept to sustainable agriculture—only with more data collection and number crunching. “We help farmers make better decisions throughout the year. For example, we can use weather stations, crop modeling, and tools to measure nitrogen in the soil to tell farmers that they should add nitrogen to a certain part of their corn field in the next 10 days.”   

Mulla believes that demand for precision agriculture is only going to grow, eventually allowing farmers to manage not only entire fields, but individual plants. “There are millions of plants in a field and precision agriculture will ultimately give us the capacity to provide each plant with a customized application,” he says. That’s already happening in some grape vineyards, but apple orchards in Minnesota may one day do this with individual trees. “Drones and robots can’t do everything, but we will be able to replace a lot of our big field equipment, which would help prevent compaction and protect our soil. It’s just a matter of time.”