Farmers from as far afield as Africa and China have flocked to see how a US farmer is harnessing precision farming techniques to boost crops yields and cut costs.
Precision farming enables farmers to use satellite positioning in smart new ways.
Clay Mitchell, based in Iowa, uses an autopiloted tractor with satellite navigation (satnav) to spray his crops. The technique is supported by 'real-time kinematics' (RTK), which takes a basic car satnav system and improves its accuracy from three metres to within 2.5 centimetres.
The technique saves fuel by eliminating driver error and remembers where it has last been — preventing plants from being sprayed twice. It also enables Mitchell to navigate his tractor along the same strips of soil, freeing up the rest of the soil.
Mitchell uses three sets of nozzles to release pesticides at different rates depending on the speed of his tractor — this means when the tractor is turning at the edge of the field, the edge still receives enough pesticide.
"If you were to figure out how much of our [precision agriculture] research is being applied by farmers, it's a low percentage," says Tony Grift, an agricultural and biological engineering professor at the University of Illinois, United States. "But [Clay Mitchell] is probably the most progressive crop farmer that we have here in America."
Farmers in the United Kingdom are also jumping on board.
Clive Blacker, one of the first UK farmers to adopt precision farming, has invented the 'N Sensor', a telephone-sized box strapped to a tractor that shines infrared light across the field and analyses the wavelengths reflected back from crops to work out nitrogen levels in the leaves. It then directs fertiliser spreaders to release appropriate amounts of fertiliser depending on crops' needs.
"Every drop goes where it is needed," Blacker says. The result is using half as much nitrogen fertiliser while increasing the yields.
A German company is now setting up a network to provide broadcasts of RTK that would allow farmers to subscribe to precision data for their machines, instead of building their own systems.