New Way to Grow Broccoli Cuts Chemicals, Saves Water and Protects Soil

Whether stir-fried, creamed, steamed, raw, or in casseroles or soup, Americans are eating more broccoli, and scientists with USDA’s Agricultural Research Service have developed a better way to grow it.

By growing broccoli in a soybean mulch, they’re using less chemicals, conserving water and eliminating soil erosion. This no-till system allows farmers to grow broccoli on the highly erodible soils of the mid-Atlantic states of Pennsylvania, Maryland, West Virginia, Virginia and North Carolina, where the terrain is often sloped.

Working with the Virginia Polytechnic Institute and State University in Blacksburg, Va., ARS scientists plant a forage soybean variety that’s high in nitrogen and grows to about 6 feet. They then cut the plants or roll them over to form a mulch to cover the soil. The thick thatch suppresses weeds, retains moisture, and protects and enriches the soil with organic matter. Broccoli requires soils rich in organic matter and high rates of nitrogen.

Results indicate that the new method produces yields comparable to those from conventional planting in bare soil. In California, where about 88 percent of U.S. broccoli is now grown, the crop is seeded in bare soil, followed by thinning and cultivation. Because weeds cause the greatest crop losses, cultivation and herbicide applications are standard and costly practices. Growers routinely apply chemical fertilizers two or three times during the growing season.

Per capita consumption of broccoli in this country reached 6 pounds last year, compared to only l.5 pounds in 1970. U.S. growers met this increased demand by producing 1.3 million pounds last year--four times the 325,000 pounds grown in 1970. Broccoli is high in vitamins and dietary fiber. Another plus: Broccoli is rich in sulforaphane, a compound associated with reduced risk of breast cancer.

The March 1997 issue of Agricultural Research magazine, the monthly publication of the Agricultural Research Service, gives more details about the new no-till way to grow broccoli. The magazine can also be viewed on the World Wide Web at:

/is/AR

Scientific contact: Aref Abdul-Baki, USDA-ARS Vegetable Laboratory, Beltsville, Md., phone (301) 504-5057, fax (301) 504-5555, e-mail vconley@asrr.arsusda.gov.