You might be surprised by how tough it is to grow one of the world's top three agricultural commodities. Even though it can be grown anywhere, rice yields useful grain only under particular circumstances. And the farther north one travels, the more difficult they are to achieve.
But according to Michael Schlappi, an associate professor with Marquette University in Milwaukee, finding efficient ways to grow rice in colder climates will soon become an important part of maintaining stable supply worldwide. He cites global climate change as reason enough to create a new industry for rice in uncultivated areas, as issues like drought and wildfires in California threaten US exports.
"Right now, the vast majority of our domestic rice is grown in California and Arkansas, because even the most tolerant plants that exist don't like cold," Schlappi says. "However, rice can be grown even in northern China or Japan, or southern Russia, which are on or around the same latitude as Wisconsin. It's just a matter of achieving good yields."
Schlappi has studied cold tolerance in plants for years, deciphering genetic codes that make for better survival rates. Through that work, he's uncovered the rice best-suited for colder climates, focusing on knowledge of existing strains, rather than methods for creating new ones.
"I picked rice over corn because corn is dominated by seed companies," Schlappi explains. "They've done a great job making it easy for farmers to grow, but they also make a huge profit at the expense of the environment. I want to make this a more sustainable practice."
His research began modestly on the roof of his own office building. According to Schlappi, there are more than 20,000 kinds of rice growing today, but the USDA lists 200 representing the vast majority of the world's varieties. He tested many of them in paddies he and his students built themselves.
"You can build a four-by-four paddy on your own roof if you wanted," he says. "We built raised beds that we filled with pool liners, then topsoil from a hardware store down the street, some compost, and sand. Then we flooded them before planting. A good 16-square foot area will give you two or three pounds of rice each year."
Using those modest practices, Schlappi has come to identify a certain Russian variety that yields well enough in Wisconsin to compete with high-volume growers.
"Our challenge was finding a kind of rice that was not only cold-resistant as a seedling in the spring, but would also flower on time before it would get too cold again in the fall," he explains. "Near the equator you can have three harvests a year because the days are so short. Up here in the summer, the days are way too long for rice to flower. So the growing seasons are shorter.
"All of that means we needed something here that could survive planting in mid-April. This Russian type happens to flower in early August, which gives it enough time before fall to fill grain, but not so much as to expose it to too much heat, which creates empty grains. Eighty percent or 90 percent of flowers need to turn into grain for useful yields. So too hot is not good for rice yields at the end of its life cycle. But too cold is bad all around.
"It was a real balancing act," he concludes.
Identifying a useful kind of rice was only the first step: Schlappi recognizes that scaling a rooftop-sized paddy to acres of farmland is the major challenge he faces now. Even having found a suitable plant variety, the infrastructure doesn't exist yet in Wisconsin to turn its cultivation into profitable enterprise.
However, by partnering with a local farm north of the city, the professor is already tackling the issue. Schlappi and his students have expanded their operation to an acre of land leased through the Fondy Farmer's Co-Op, which offers fields to those willing to sell their crops at a farmer's market in Milwaukee's inner city. That's given the operation a chance to try out new methods, unencumbered by market expectation.
"We need to train contractors to build the paddies, there are materials we need, there is machinery we need," Schlappi explains. "We need a mechanized way of planting the seedlings into the paddy, and a way to drain them when the season's over. None of that exists here yet. But it's a chance to create jobs for those who can't find work. We just have to make it easy enough—we don't want to push anything that pushes rice into the Stone Age."
And what about the yield they're seeing outside? "We're already growing two or three pounds of rice per 16-square-foot paddy each year," Schlappi says. "That translates into 7,000 or 8,000 pounds of rice per acre, in an undeveloped market. It's a significant opportunity, and one that would allow our state to compete with the country's biggest producers."