Some scientists want to get rid of that — all but the harvesting part, that is.
A small number of agricultural scientists are working on what they say are the crops of the future — plants that grow perennially, like grass, and therefore need less of the intensive fertilizing and plowing of modern agriculture, which some say encourages soil erosion and pollution.
Wes Jackson, founder of the 580-acre Land Institute, came up with Natural Systems Agriculture, a model that includes developing strains of perennial wheat, sorghum, sunflowers and corn, which, like prairie grasses, would come back every year on their own and produce enough grain to be marketable. The goal is to save soil and reduce or eliminate the use of chemicals and irrigation.
The grains wouldn't be planted in orderly rows as they are now. Instead, like the prairie in its natural state, a perennial grain would be scattered throughout a field.
"I envisioned something where agriculture worked like the prairie, with a lot less input," said Jackson.
As perennials, Jackson says, the crops would need fewer chemicals to fend off weeds and insects, and would get their moisture not from irrigation but from vast root systems that would soak up snow and rain.
The Land Institute, which is funded through grants and membership fees, now has a 25-year plan for its goals and employs six scientists who work at developing the perennial crops. The institute also funds 19 graduate fellows at universities across the nation.
Stephen Jones, an associate professor at Washington State University in Pullman, is one of the only other scientists outside the Land Institute who has been working on perennial wheat in the United States. He says crossing wheat with its wild cousins to make it a perennial is not a popular academic research choice.
"It's looked on as a bit of quackery," Jones said. "And I don't know how that started. It's not like we're asking the plants to make their own bagels."
"It's not that big of a leap biologically."
Jones's research is slightly ahead of the Land Institute's. He has wheat plants in the field that have come back for four years. Their yields are low, but Jones said that doesn't concern him, and it shouldn't concern the Land Institute.
"Wes's idea of the prairie system ... is way out there in the future," said Jones, who sits on a Land Institute advisory board. "We need that. The land grant (universities) right now are pretty conservative places."
But Allan Fritz, an associate professor at Kansas State University in Manhattan, says potential low yields from perennial wheat raise concerns about viability.
Gary Melander farms about 2,500 acres south of Salina. He doesn't care if the institute's perennial wheat has good yields because he gets something more from Jackson's efforts.
"The people at the Land Institute give me inspiration," Melander said.
Jackson, 67, doesn't put a lot of store in schedules and in whether he will live to see farmers in Kansas or anywhere else harvesting perennial crops.
And he gets a little impatient when asked how long it will take to achieve his dream of turning agriculture on its head.
"All these people want Wal-Mart science, instant gratification, fast and cheap," Jackson says. "But, you know, if you're working on something you can finish in your lifetime, you're not thinking big enough."
According to the EPA, agriculture is the main cause of pollution in 48 percent of tainted U.S. waterways and 18 percent of all river and stream miles.