| Department of Agronomy Newsletter | Fall 1999 |
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Lynn Hoffman retires One of the country's foremost experts in no-till farming recently retired from the department. Lynn Hoffman, senior research associate, was part of a team that for the past 30 years has promoted and fine-tuned management techniques for no-till farming. This team was responsible for the adoption of no-till throughout much of the Northeast and its eventual spread into the Midwest. "We started exploring this option in the interest of reducing soil erosion," says Hoffman, "but just as importantly, we were able to develop no-till systems that are successful and cost-effective and provide farmers with a wider opportunity to manage their time and resources for profit." He estimates that no-till farming results in a 60 percent decrease in labor hours. "The dramatic reduction in the number of labor hours it takes to grow an acre of no-till corn versus conventionally grown corn often allows farmers to expand their corn acreage from 100 acres to 200 acres, for example" says Hoffman, "because the crop requires less labor." He estimates that well over half of Pennsylvania farmers now use no-till techniques on at least part of their acreage and that about 30 percent of the state's corn crop and 20 percent of the alfalfa crop is grown in no-till fields. The technique is particularly well suited for the small, rocky, hilly fields typical of Pennsylvania farms, which make operating a large piece of machinery difficult and uneconomical. Maryland, Pennsylvania, and Delaware farms make the greatest use of no-till techniques. |
Working for soybean growers in Pennsylvania Several faculty members in the department are working to determine how to optimize soybean yields in Pennsylvania. Because most new soybean varieties are now developed and tested in the Midwest, Elwood Hatley, professor of agronomy, is collaborating with John Yocum, senior research associate, to evaluate new varieties under Pennsylvania's somewhat different growing conditons. The Pennsylvania Soybean Promotion Board has funded tests at the Russell E. Larson Agricultural Research Center in central Pennsylvania and at Landisville in Lancaster County. Until about 15 years ago, Pennsylvania farmers grew only 50,000 to 60,000 acres of soybeans, primarily in the more mild southeast corner of the state. Although the crop is still concentrated there, soybeans are now grown across much of central Pennsylvania as well, bringing the total acreage to about 400,000. "The rapid growth in soybean acreage is related to the establishment of a processing plant on the Eastern shore of Maryland," says Hatley, "and to the aggressive development of new markets that has increased the profitability of soybeans." Most of the soybeans grown in the state are exported off the farm, but some are used for animal feed. Hatley and Yocum are evaluating optimal soybean management techniques such as planting date, seed treatments, and row spacing. Their research indicates that the optimum planting date for soybean is early- to mid-May. They've found that soybean can be planted earlier than this without greatly reducing yields, thus offering producers a wider window for planting. "Soybean performs best when planted in rows 15 inches or less," says |
Hatley. "If a producer wants to plant in wide rows, say 30 inches, the soybean should be planted by May 10 to reduce the potential yield loss." With the trend toward earlier planting , Hatley and Yocum have tested a number of seed treatments that protect the seed from disease organisms when planted early in cold soils (~50°F). They did not find any advantage in using these treatments. They also have made yield comparisons of herbicide-resistant and conventional varieties. The market for herbicide-resistant soybeans has seen exponential growth in the three years since introduction. They now constitute about 60 percent of the soybeans grown in Pennsylvania. Hatley credits the ease of use and successful weed eradication for the phenomenal acceptance of these varieties. However, says Hatley, "My experiments with John Yocum show that herbicide-resistant varieties produce a slightly lower average yield than do non-resistant varieties." Bill Curran, associate professor of weed science, has been researching weed control in soybeans. Among other things, he is evaluating Roundup Ready soybeans to determine how their interaction with Roundup Ready soybeans to determine how their interaction with Roundup Ultra herbicide can be manipulated to maximize yield. "We've found that Roundup Ready soybeans in Pennsylvania produce the highest yields and have less weed problems when planted in rows that are at most 15 inches wide," says Curran. He advocates planting soybeans in narrow rows using a grain drill or planter to maximize crop competition. He also notes that many Pennsylvania farmers are applying Roundup Ultra too long after weed emergence for maximum effectiveness. He recommends spraying about four weeks after planting. Curran's research has shown Roundup Ready technology |
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