COLUMBUS, Ohio - The practice of growing fruits and vegetables on raised beds has proven to be successful for blueberries, providing growers with a cheaper, more beneficial alternative production method.
Ohio State University research has found that blueberries grown on raised beds produced comparable yields to blueberries grown on flat, tile-drained soil. "We can say with 90 percent certainty that raised beds are sufficient for blueberries," said Dick Funt, an Ohio State horticulturist. "There's no need to install a costly tile drainage system when a grower can get equal or better yields on raised beds." The results are part of an Ohio State South Centers at Piketon study to identify crops that can be successfully grown on raised beds. The researchers are in their third year of blueberry harvest.
The traditional method of raising blueberries involves growing the fruit on flat soil and installing a tile drainage system 32-to-36 inches deep within the soil.The system is designed to remove excess water. Blueberry plants have shallow root systems that lack root hairs, which are normally used to increase the root's surface area for water and nutrient uptake. The lack of root hairs makes the blueberry plant sensitive to changing soil and water conditions.
Growing blueberries on raised beds has a variety of benefits that the tile drainage system may not provide, said Funt. It's more economical. The cost of making a raised bed is about $350 as compared to tile drainage at or above $1,500 per acre.
It's also better for the plant, Fund said. A raised bed involves creating topsoil that is 8-10 inches higher than the normal soil surface. The idea is to improve soil conditions, eliminate compaction and better regulate irrigation.
"Ohio soils are generally cold and damp. With raised beds we are creating an environment for roots to be less cold and less wet since raised beds help to warm the soil," said Funt. "Also, it's known that roots are located in the upper 12 inches of the soil. With raised beds, we are making sure the roots get just enough of the water and nutrients it needs. As a result, we get better production - a better root, a better plant, and over time, more plants surviving per acre."
Raised beds are normally installed in the fall so that the soil is prepared for planting come spring. The last census in Ohio reported about 280 acres of blueberries, most of which are grown in northern Ohio.
The practice of growing blueberries on raised beds may also provide a marketing advantage for growers who can consistently produce a successful crop throughout its 20-25 year life cycle to help feed a slowly growing consumer demand.
Blueberries rank second behind strawberries in per capita consumption. Fresh/frozen blueberry consumption is less than a pound per year, while nearly five pounds of fresh/frozen strawberries are consumed per year.
Though not as popular as strawberries, blueberries are getting noticed for the health benefits they may provide. Research has shown that blueberries have antioxidants and other compounds which help fight off various cancers; are high in fiber; may help reverse problems associated with aging; and contain concentrated tannins, compounds that have been found to prevent urinary infections and are absent in such fruits as apples and oranges.
Researchers are also pushing a new food group classification - a colorful lot of red, orange-yellow, green and blue-purple to encourage consumers to eat more fruits and vegetables. Blueberries, for example, would fall under the blue-purple category. The idea is that color is everything - the more intense a food's pigment, the greater disease-fighting properties the food has.
"It's an easier way for consumers to identify fruits and vegetables that are good for them," said Funt. "Consumers are so overloaded with information. This classification simplifies the whole process of choosing and mixing fruits and vegetables they should be eating on a daily basis."
The new classification may also help consumers focus on specific fruits or vegetables based on research being conducted. "For example," said Funt, "if research is finding that blue-purple fruits help counteract certain health problems, then consumers could up their level of blue-purple intake."