Soybean growers in Virginia may be able to receive an additional $2.25 per bushel for their soybean crop, if they are willing to grow edible beans. The opportunity to get that kind of premium price for Virginia beans will increase in 2007, according the Virginia Tech Soybean Specialist David Holshouser.

The primary reason for the increased opportunity is the establishment of a natto bean buying site by Montague Farms in southeastern Virginia. This will significantly increase the demand for edible beans for export to Japanese markets, Holshouser explains.

In the past in Virginia yield has been a problem. Natto beans have only yielded about 80 percent of the yield of conventional beans grown for oil and livestock feed.

MFS-591 is the ‘gold standard’ for natto soybean varieties, because of its high quality. Virginia Tech soybean breeders have been able to develop varieties with yield potential comparable to conventional beans, but these varieties have not met quality standards of MFS-591.

Natto soybeans are small (maximum of 5.5 mm diameter), clear hilum soybeans with thin seed coats and high carbohydrate content. They are typically grown for fermented soybean foods called Natto in Japan, thus the name Natto Soybeans.

The fermentation process breaks down the beans' complex proteins, making them more easily digested than whole soybeans. Natto is reported to have higher levels of isoflavone than either soymilk or tofu.

Natto soybean production has nearly disappeared in the U.S. due to increased production in Japan related to low rice subsidies. Therefore, premiums are nearly non-existent and are not competitive with GMO soybean production.

There is a small pocket of Natto soybean production in Arkansas, Virginia and in southern Canada.

In the upper Southeast, corn is a staple rotation crop with soybeans, including natto beans. It is critical for growers to eliminate any standing corn from the field before harvest to prevent corn contamination.

Natto growers also have to make some equipment adjustments to compensate natto's small seed size and to keep seed damage to an absolute minimum. Harvesting equipment, especially the combine platform, must be carefully calibrated to avoid picking up soil, which can contaminate food-grade soybeans.

In the lower South, the University of Florida has tested natto varieties for a number of years. Varieties which have been tested in Florida in recent years include ‘Verde,’ ‘Disoy,’ ‘Bansei,’ and ‘Giant Green.’ All of these make good green crops and produce many pods suitable for fresh table usage.

The pods must be harvested when the beans are in a mature green stage. As they mature, fungus diseases become quite destructive.

Virginia Tech researchers have found yield advantages to be more consistent when soybeans follow corn in rotation. Insect and disease control also benefits from the corn and soybean rotation, and problems with difficult to control weeds are decreased.

High quality, small-seeded natto soybeans are achieved with planting rates of 200,000 seeds per acre for drilled or 7 to 8 plants per foot in 30-inch rows (140,000 to 150,000 seeds per acre). Because of the small seed size (5.5 mm diameter) it is sometimes difficult to maintain accurate plant population. Natto soybeans usually have about 6,000 seeds per pound.

Katy Rainey, a plant breeder at Virginia Tech says, “flavor, color and seed hardness are critical quality factors in the small seeded natto beans. Our breeding material is among the best in the world, and these beans are in high demand in Japan.” The challenge, she says is to incorporate all these traits, plus yield potential, into one variety.

Rainy says much of the funding for development of natto soybean varieties comes from Montague Farms.

Montague Farms, Inc. contracts with growers over a radius of 200 miles from southern Maryland through eastern Virginia into northeastern North Carolina. These growers have grown certified soybean seed for many years and have a reputation for producing high quality soybeans.

Because the geographic area in which Montague Farms' natto beans are grown is extensive, local adverse growing conditions such as drought, flood or hail are minimized.

Contract growers work closely with Montague Farms' director of grower relations, who advises growers and monitors seed procurement, planting, tillage and cultural practices, pest control, harvest and delivery.

In addition, during the growing season every field is inspected by a reputable field inspection service.

David Cook, a graduate student at Virginia Tech, working in the natto bean program, says very little processing is done to these edible beans that are grown predominantly for export to Japan. Once beans get to Japan, they are steamed and fermented, so quality of the bean going into the process really affects the product that comes out.

Cook says Virginia Tech is looking at 12 Group IV and Group V natto bean varieties, grown both full season and double-cropping. “We grow them under different soil types and weather conditions, so we can evaluate them under a wide range of grower conditions,” Cook says.

Cook says it is important to develop new varieties that are consistent across a range of soil and climatic conditions. Qualities, like water absorption and seed coat strength, are critical to the value of these beans, because it directly affects the processing costs. Lighter colors and chemical components that affect flavor are also important, he says.

Holshouser, who has headed Virginia Tech's soybean program for 10 years says the addition of natto beans as a niche crop for Virginia growers brings some challenges to both soybean growers and researchers. “Hogs, cattle and chickens may not be too particular as to how soybeans taste, but the people who eat edible beans are keenly aware of it,” he says.

Holshouser adds that any one in the Tidewater area interested in growing natto beans should contact him for information about marketing opportunities.