PIERRE - They're a blip in the data when they first show up in South Dakota in the statistics from 1939. That's the year when a few farmers in the state plant a total of 2,000 acres of that new crop, soybeans. There's no record of how many acres they harvest; but the next year, 1940, farmers plant 4,000 acres, and harvest 1,000; in 1941, they plant 6,000 acres, and harvest 2,000.
In 1954, the acres devoted to soybeans in the state surge well past 100,000 for the first time.
And by 1980, when Lewis Bainbridge is thinking of growing them on his farm near Ethan in Davison County, nearly 800,000 acres of soybeans are already growing in South Dakota.
''My wife and I started farming in 1977. At that time we were still planting corn and some small grains - basically oats,'' says Bainbridge. ''We were looking for a different cash crop.'' Though happy with the corn, Bainbridge wasn't satisfied with either the yields or the prices for oats.
He gave soybeans a try at the start of the 1980s and he's never looked back - a story that is similar for a great many producers all across eastern South Dakota. Soybeans, a crop the first generations of South Dakotans knew nothing about, have nestled into the South Dakota landscape like beans in a pod.
The acres devoted to soybeans in South Dakota passed the 1 million mark in 1984, reached the 2 million mark in 1991, hit 3 million in 1997 and passed the 4 million mark in 1999.
In 2012, South Dakota farmers planted 4,750,000 acres of soybeans and harvested 4,650,000.
Bainbridge, who is on the United Soybean Board, the group that oversees the national soybean checkoff, sees the decades-long shift to more soybeans as good for South Dakota. For one thing, South Dakota is at the western edge of the soybean-producing area of the United States. That means it is closer than most soybean-producing states to Asian export markets by railroad. More than 60 percent of South Dakota's soybeans are exported.
''Most of them go to the Pacific Northwest, to the Asian market,'' Bainbridge said.
Some 30 miles southeast of Pierre, producer Colin Nachtigal of rural Harrold, who farms with his brother, Jason, said soybeans have been a good fit for their operation near the Missouri River. They grow them on irrigated land as well as on dryland acres.
But as with Bainbridge's move away from oats, Nachtigal said their cropping patterns show cereal grains - especially spring wheat and oats - losing ground to soybeans.
''We've been growing less wheat. We really don't do oats or spring wheat,'' Nachtigal said. ''On our dryland, we try to do a corn, soybean and winter wheat rotation. In 2011, we had some 40-bushel soybeans down here on dryland, which is probably the best we've ever had down here.''
And in 2012, despite the drought that crippled dryland production, Colin's brother, Jason, produced 85.95 bushels an acre on irrigated land - good enough for second place in his group category, and third overall in the South Dakota Soybean Yield Contest sponsored by the South Dakota Soybean Association.
The Nachtigals have been growing soybeans on their farm near Pierre since about 1992, Colin said. He believes in the crop enough that he is now a board member of the South Dakota Soybean Association.
A considerable amount of research has looked at both the health benefits and health risks that are claimed for soybeans. The United Soybean Board's perspective, especially regarding possible health benefits, is available at a website, http://www.soyconnection.com. Research is also continuing on ways to make soybeans better as a feedstock for biodiesel.
One thing is clear: The crop produces far more protein per acre than most other ways of using the land.
''It's what the world's demanding. You've got China and India demanding protein,'' Nachtigal said. ''We're just doing the best we can to grow it.''
In central South Dakota, that brings some challenges.
''Probably one of the biggest challenges with soybeans is that they really need some water in late July or August. That can be really tough to come by out in this part of the country,'' Nachtigal said.
On the other hand, Nachtigal and Bainbridge said moisture-saving no-till farming has helped soybeans move west; and seed companies have done a good job coming up with soybean lines that have helped expand the soybean production area.
''The major companies are breeding some varieties that work for those drier, shorter growing seasons areas,'' Bainbridge said.
Bainbridge says as positive as the soybean impact has been on South Dakota, he would like to see soybeans adding to the state's economy in new ways. Though a United Soybean Board study showed that South Dakota had 16 ethanol plants as of July 2012, adding value to the state's corn production, it had only one soybean crushing plant, in Volga.
The state could use more such soybean crush facilities to supply soybean meal as a feed ingredient for livestock operations, Bainbridge said.
''I'm a huge livestock guy,'' Bainbridge said. ''I'd really like to see us crush our beans here in South Dakota and feed our livestock and then sell the meat, both to meet our domestic needs and for export.''