The orange Agco tractor whines under the strain of the huge corn planter it is tugging through Matthew Bennett's field. Inside the cab, a computer display tells Bennett how fast he is going and how much seed he is dropping as he steers the tons of bouncing steel over uneven ground.

With one eye on the field, Bennett picks up his cell phone to check the grain markets. A few minutes later, he is on the phone again, this time with his father who is tracking a rain storm.

"It's a situation where you want a shower, but you don't want a toad strangler," Bennett says, referring to heavy rain that could stop planting for the day.

Planting corn and soybeans on more than 3,000 acres of prime east-central Illinois soil marks the beginning of another growing season, and the first test of decisions made long before the tractors were tuned up this spring.

Those decisions -- especially the type of custom-designed corn and soybean seeds to be planted -- will go a long way toward determining whether Matt Bennett and his father, Tim, turn a profit this season on the land they farm near Shelbyville and Windsor, about 170 miles south of Chicago.

But, ultimately, nature plays the biggest role in determining how well the crop will grow. And then the grain markets set the price.

"You can do everything perfect and it's still not up to you," says Bennett's wife, Lori. "We learned a long time ago that things are not in our hands."

Not long after last fall's harvest, the Bennetts chose from hundreds of corn hybrids and dozens of soybean varieties which to plant this spring, as well as which fertilizer and weed spray to use.

They will spend $35,000 to $40,000 to plant corn seeds that have been coated with pink or purple insecticide. The pink controls several bugs, including wireworms, which feed on germinating seeds and early seedlings. The purple seeds have a higher concentration of insecticide, which goes into the plant to control rootworm, a destructive pest that eats away at a corn plant's roots and causes the stalk to collapse.

Soybean seeds add $15,000 to the bill. Fertilizer, herbicide, rent and other costs mean the Bennetts will spend about $300 per acre to grow crops this year.

If the seeds they chose do not grow well because of the soil, if they spray the weeds too early or if they spray the weeds too late, it means lower yields and lost money.

Bennett plants only about 160 acres, or about 15 percent of their total corn acreage, with genetically engineered corn, well below the statewide average of 35 percent.

Growing biotech corn takes extra effort to keep it out of the export chain to the European Union and other countries that do not approve of gene modification. Archer Daniels Midland Co., to which the Bennetts will deliver most of their grain, does not accept some types of biotech corn because of the risk that it will mix with other corn and cause whole shiploads of grain to be rejected by an importing country.

So at harvest time, Bennett has to segregate his biotech acres to guard against that problem. Biotech seeds also cost about $30 more per bag, Bennett said.

Like most Illinois farmers, the Bennetts plant about 80 percent of their soybean acreage with seeds that are genetically modified to tolerate Roundup, a herbicide that kills nearly every plant it touches. Bennett also plants about 200 acres of non-GMO, food-grade soybeans for U.S. Soy in nearby Mattoon, which will turn them into soy flour, soy milk powder or soy nuts, as well as seeds for next year's crop.

The crops provide a living for the Bennetts and continue a family vocation that began more than 130 years ago -- a vocation that Matt and Lori Bennett hope to pass on to their son. But Bennett knows that keeping the family farm going will only become more challenging, even in a state rich with farm tradition, where agriculture and its related businesses still constitute the No. 1 industry.

"I hope that he carries on the tradition," Bennett said of his 3-year-old son, Beau. "But if farming changes much more, golly it's going to be tough."

The family's operation, already almost three times larger than the average Illinois farm, will have to grow even more by the time Beau decides whether to become a sixth-generation farmer, Bennett said. Second incomes are critical to most farm families, and farmers will have to become more efficient to keep expenses down, perhaps by working with their neighbors.

"I think to survive and thrive we may need to have to look at giving up a small amount of our independence in order to maybe be able to operate a little more efficiently," Bennett said.

Bennett's $125,000, 24-row John Deere planter can plant 50 acres in about an hour. It drops about 30,000 seeds per acre into the furrows it creates, reducing planting time for 3,000 acres to about 10 days.

Bennett has already started marketing the crop, selling about 40,000 bushels of corn and soybeans before they grow to take advantage of the high prices early in the year. He now knows how much he will receive for about 20 percent of his crop, assuming nature provides at least an average harvest.

For now, the long hours in the tractor are done, and Bennett and his family begin the long watch for rain and pests, and pray that the prices stay high.