This is not your grandfather's tractor:
The techniques, known as precision agriculture, incorporate global positioning systems and digital mapping software linked to machines that apply just the right number of seeds and just the right concentrations of fertilizers and herbicide to get the most out of the fields...
Precision agriculture has gone from largely experimental to mainstream since the mid-1990s, and more technology is on the horizon: narrow robots that chug down corn rows to zap weeds or squirt fertilizer and drones that hover above cropland taking pictures of insect infestations...
Precision agriculture figured out how to produce fertilizer prescriptions tailored to individual fields, Mulla said, so that more nutrients were applied where they were needed and less where they weren’t. He estimates that 30 percent to 40 percent of corn and soybean farmers in the Upper Midwest now use variable rate fertilizer systems. The same principle has been followed with herbicides, insecticides and seeds, he said, so that farmers waste less and save more.Today, variable seed planters and chemical spreaders link to digital mapping programs that automatically adjust to deliver at different rates as they’re driven across a field. Yield monitors measure the number of bushels of corn or soybeans instantly as they’re being harvested in the field. Global positioning systems connect directly to hydraulic steering mechanisms that allow tractors and combines to run on autopilot.
I knew the technology allowed more limited use of fertilizer; I hadn't heard about the yield monitors, but they certainly make sense. I totally applaud this application of technology to limit the broadcasting of herbicides and fertilizer.
This is an amazing degree of change within one generation. My mother (95 years old) vividly recalls her experience as a child on a Minnesota farm:
She was born in 1918 to a classic 2nd generation Norwegian immigrant family in southern Minnesota, in an era when children were expected to help work the farm. She wore a huge bonnet in the summer sun, so that neighbors said it looked "like a big hat was driving the rig." She learned to drive that team of horses in a straight line so the cultivating tines wouldn't disturb the planted corn. She was 8 years old at that time.
And she cross-cultivated that corn (north-south, then east-west); now the corn is planted so close together you can't walk across the rows. The yield of a field is probably 4X as great now just based on number of plants, not to mention the hybridization of the cobs themselves.
It wasn't that long ago that the addition of a plastic "cab" to a tractor to protect the farmer from the elements was an innovation. Then a radio. And air-conditioning. And a cell phone. Now satellite linkage and computers. It's a whole new world - within one human generation. It boggles the mind.
There's more information at the StarTribune article; photo credit Bruce Bisping.