Sara Alberts wasn’t far behind, however. And she very nearly beat her son-in-law back to the starting point in her trip around the parking lot behind the wheel of the half-story high, two-lane wide farm implement.

It was not your average family outing at the outset of a PGA TOUR tournament week but John Deere equipment and the John Deere Classic just happen to combine two of the foremost passions of Oosthuizen, the 2010 British Open champion who currently is ranked 138th in the FedExCup standings but 10th in the world.

“I’ve still got quite a bit of passion for golf, but John Deere and farming is not far off,” said Oosthuizen, who will lead a field that includes Keegan Bradley, three-time winner Steve Stricker and defending champion and hometown favorite Zach Johnson into action beginning Thursday at TPC Deere Run in Silvis, Ill. “That’s why this week is so special to me.”

The tour around the John Deere Harvester plant was the second in three years for Oosthuizen, who teed it up in his first John Deere Classic just one week before he defended his British Open title in July of 2011.

In addition to his mother-in-law, he was accompanied Tuesday by his parents, Piet and Minnie Oosthuizen, and his father-in-law, Nick Alberts, for the two-hour guided tour through one of the original John Deere plants. The group later toured John Deere’s world headquarters in Moline along with Oosthuizen’s wife, Nel-Mare, and their three daughters.

Piet Oosthuizen said his curiosity about John Deere equipment couldn’t possibly match his son’s, but his interest was obvious as the morning tour progressed. The champion golfer’s father learned both the art of dairy farming and the love of John Deere tractors from his own father, who he remembers purchasing a shiny new Model A tractor way back in 1957.

“Everyone in our family loves John Deere,” said the senior Oosthuizen, who continues to work the family farm near the quiet South African town of Albertinia. “If you buy a tractor, you buy a John Deere. I don’t think there will ever be anything else on our farm.”

The in-laws can’t say the same. Nick Alberts said there is mix of farm implement brands in the barns of the family’s inland farm on South Africa’s northern cape. A few of his tractors are John Deere green, he said, but not all.

Louis Oosthuizen overlooked that when he asked for the hand of Nel-Mare Albert, a childhood acquaintance. But he said he is working on a full “greening” of the farm where Nick Alberts grows wheat and raises sheep.

“I’m getting him there,” the 30-year-old golfer said under the shadow of a S690 combine parked in the lobby of the factory’s visitor center. “They’ve got a few John Deere products, but I am still trying to get him into one of these.”

Louis Oosthuizen has no need for a combine on the 150 acres where he raises cattle on the Indian Ocean coast near his parents’ farm. He is eager, however, to step into the new John Deere R450 Windrower tractor he recently ordered. It will join a 6000 Series John Deere tractor that was among the first items he purchased with his British Open winnings.

Piet Oosthuizen said his son’s love of John Deere green knows no end.

“You can ask him anything about John Deere,” the father said. “He is on the computer every day, and he knows every spec of every piece of John Deere equipment. He loves it.”

That makes Oosthuizen slightly unique among his PGA TOUR cohorts, the golfer conceded. But he is OK with that.

And whatever happens when this year’s John Deere Classic tees off Thursday at, it seems a safe bet Oosthuizen will be back for more in the future. There’s a John Deere tractor plant a couple of hours away in Waterloo, Iowa, he said he is eager to see.